High frequency line-to-waveguide converter and high frequency package Number:7,522,014 from the United States Patent and Trademark Office (PTO) owispatent A high frequency line-waveguide converter comprises a high frequency line including a dielectric layer, a line conductor disposed on an upper surface of the dielectric layer, and a ground conductor layer disposed on the same surface so as to surround one end of the line conductor, a slot formed in the ground conductor layer so as to be substantially orthogonal to the one end of the line conductor and coupled to the line conductor, a shield conductor part disposed on a side of or in an inside of the dielectric layer so as to surround the one end of the line conductor and the slot, and a waveguide disposed at the lower side of the dielectric layer so that an opening is made opposite to the one end of the line conductor and the slot, and electrically connected to the shield conductor part.<H frequency, converter, High, frequency, , 7522014.html, Patent, pto, 7522014

Title: High frequency line-to-waveguide converter and high frequency package

Abstract: A high frequency line-waveguide converter comprises a high frequency line including a dielectric layer, a line conductor disposed on an upper surface of the dielectric layer, and a ground conductor layer disposed on the same surface so as to surround one end of the line conductor, a slot formed in the ground conductor layer so as to be substantially orthogonal to the one end of the line conductor and coupled to the line conductor, a shield conductor part disposed on a side of or in an inside of the dielectric layer so as to surround the one end of the line conductor and the slot, and a waveguide disposed at the lower side of the dielectric layer so that an opening is made opposite to the one end of the line conductor and the slot, and electrically connected to the shield conductor part.

Patent Number: 7,522,014 Issued on 04/21/2009 to Koriyama

Inventors: Koriyama; Shinichi (Kokubu, JP)
Assignee: Kyocera Corporation (Kyoto, JP)

Appl. No.: 11/841,442

Filed: August 20, 2007

Related U.S. Patent Documents


Application Number	Filing Date	Patent Number	Issue Date
10696745	Oct., 2003	7276987

Foreign Application Priority Data


Oct 29, 2002 [JP]			2002-314410
Mar 27, 2003 [JP]			2003-087350

Current U.S. Class: 333/26 ; 333/246

Current International Class: H01P 5/107 (20060101); H01P 3/12 (20060101)

Field of Search: 333/26,239,246,248 428/209 343/767

References Cited [Referenced By]

U.S. Patent Documents


5982256	November 1999	Uchimura et al.
6060959	May 2000	Yakuwa
6239669	May 2001	Koriyama et al.
6359590	March 2002	Takenoshita
6535090	March 2003	Matsuzuka et al.
6572955	June 2003	Terashi et al.
6580335	June 2003	Iizuka et al.
6822528	November 2004	Dawn et al.
6888429	May 2005	Okajima et al.

Foreign Patent Documents


0 905 814	Mar., 1999	EP
2001-177312	Jun., 2001	JP
96/27913	Sep., 1996	WO

Primary Examiner: Takaoka; Dean O
Attorney, Agent or Firm: Hogan & Hartson LLP

Parent Case Text

CROSS-REFERENCE TO THE RELATED APPLICATIONS

This is a divisional of application Ser. No. 10/696,745 filed Oct. 29, 2003, the entire contents of which are incorporated by reference. This application also claims benefit of priority under 35 USC .sctn. 119 to Japanese Patent Application No. 2002-314410 filed Oct. 29, 2002 and Japanese Patent Application No. 2003-087350 filed Mar. 27, 2003, the entire contents of both of which are incorporated by reference.

Claims

What is claimed is:

1. A high frequency package comprising: a metal base having a mounting part of a high frequency electronic component on one surface, and a through hole disposed to be adjacent to the mounting part, an opening on one side of the through hole being connected with a waveguide; and a high frequency line-to-waveguide conversion substrate joined on an opening on another side of the through hole, the high frequency line-to-waveguide conversion substrate including: a high frequency line including: a dielectric substrate; a high frequency line conductor directed from an outer peripheral part to a center part on one surface of the dielectric substrate; and a same surface ground conductor disposed on the same surface as the one surface of the dielectric substrate so as to surround an end of the high frequency line conductor on the center part side, a frame ground conductor formed on another surface of the dielectric substrate in a shape conforming to an opening on another side of the through hole so as to be opposite to the end of the high frequency line conductor on the center part side; a slot provided on the same surface ground conductor and formed to be orthogonal to the end of the high frequency line conductor on the center part side and coupled to the high frequency line in terms of high frequency; and a connection conductor for connecting the same surface ground conductor and the frame ground conductors, wherein the high frequency line-to-waveguide conversion substrate is joined on the other side of the through hole such that the high frequency line is positioned on a side of the mounting part and the frame ground conductor is made to conform to the opening on the other side of the through hole.

2. The high frequency package of claim 1, wherein an interval between the high frequency line conductor and the same surface ground conductor is 1/4 or less of a signal wavelength of a high frequency signal transmitted through the high frequency line.

3. A high frequency package comprising: a metal base having a mounting part of a high frequency electronic component on one surface, and a through hole disposed to be adjacent to the mounting part, an opening on one side of the through hole being connected with a waveguide; and a high frequency line-to-waveguide conversion substrate joined on an opening on another side of the through hole, the high frequency line-to-waveguide conversion substrate including: a high frequency line including: a dielectric substrate; a high frequency line conductor directed from an outer peripheral part to a center part on one surface of a dielectric substrate; and a same surface ground conductor disposed on the same surface as the one surface of the dielectric substrate so as to surround an end of the high frequency line conductor on the center part side, a frame ground conductor formed on another surface of the dielectric substrate in a shape conforming to an opening on another side of the through hole so as to be opposite to the end of the high frequency line conductor on the center part side; a slot provided on the same surface ground conductor and formed to be orthogonal to the end of the high frequency line conductor on the center part side and coupled to the high frequency line in terms of high frequency; an internal ground conductor formed between the high frequency line conductor of an inside of the dielectric substrate and the frame ground conductor, and provided with the transmission opening opposite to the slot and larger than the slot; a first connection conductor for connecting the same surface ground conductor and internal ground conductor; and a second connection conductor for connecting the frame ground conductor and the internal ground conductor, wherein the high frequency line-to-waveguide conversion substrate is jointed on the other side of the through hole such that the high frequency line is positioned on a side of the mounting part and the frame ground conductor is made to conform to the opening on the other side of the through hole.

4. The high frequency package of claim 3, wherein an interval between the high frequency line conductor and the same surface ground conductor is 1/4 or less of a signal wavelength of a high frequency signal transmitted through the high frequency line.

5. A high frequency package comprising: a metal base including a mounting part for a high frequency electric component on one surface thereof, a through hole disposed to be adjacent to the mounting part and having an opening on one side connected with the waveguide, being formed therein; and a conversion substrate, including: a high frequency line including: a dielectric substrate; a high frequency line conductor formed on one surface of the dielectric substrate and disposed so as to extend from an outer peripheral part toward a center part on the one surface of the dielectric substrate; and a same surface ground conductor disposed on the same surface as the one surface of the dielectric substrate so as to surround an end of the high frequency line conductor on the center part side, a frame ground conductor formed on another surface of the dielectric substrate in a shape conforming to an opening on another side of the through hole so as to be opposite to the end of the high frequency line conductor on the center part side; a slot provided on the same surface ground conductor and formed to be orthogonal to the end of the high frequency line conductor on the center part side and coupled with the high frequency line conductor in terms of high frequency; and a connection conductor for connecting the same surface ground conductor and the frame ground conductors, wherein the conversion substrate is joined on the other side of the through hole of the metal base such that the high frequency line is positioned on the side of the mounting part of the metal base and the frame ground conductor is made to conform to the opening on the other side of the through hole of the metal base.

6. A high frequency package comprising: a metal base including a mounting part for a high frequency electric component at one surface thereof, the through hole disposed to be adjacent to the mounting part and having an opening on one side thereof connected with the waveguide, being formed therein; and a conversion substrate including: a high frequency line including: a dielectric substrate; a high frequency line conductor disposed so as to extend from an outer peripheral part toward a center part on one surface of the dielectric substrate; and a same surface ground conductor disposed on the same surface as the one surface of the dielectric substrate so as to surround an end of the high frequency line conductor on the center part side, a frame ground conductor formed on another surface of the dielectric substrate in a shape conforming to an opening on another side of the through hole so as to be opposite to the end of the high frequency line conductor on the center part side; a slot provided on the same surface ground conductor and formed to be orthogonal to the end of the high frequency line conductor on the center part side and coupled with the high frequency line conductor in terms of high frequency; an internal ground conductor formed between the high frequency line conductor of an inside of the dielectric substrate and the frame ground conductor, and provided with the transmission opening opposite to the slot and larger than the slot; a first connection conductor for connecting the same surface ground conductor and internal ground conductor; and a second connection conductor for connecting the frame ground conductor and the internal ground conductor, wherein the conversion substrate is joined on the other side of the through hole of the metal base such that the high frequency line is positioned on the side of the mounting part of the metal base and the frame ground conductor is made to conform to the opening on the other side of the through hole of the metal base.

Description

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a high frequency line-to-waveguide converter in which a high frequency line, such as a coplanar line or a coplanar line having ground, forming a high frequency circuit and used in a microwave or millimeter wave region is converted into a waveguide, and connection between the high frequency circuit and an antenna or between high frequency circuits is performed through the waveguide, so that mounting of a system can be easily performed.

Besides, the invention relates to a high frequency package for easily connecting a high frequency electronic component used in a microwave or millimeter wave region to a waveguide.

2. Description of the Related Art

In recent years, we enter the advanced information age, and with respect to a high frequency signal used for information transmission, studies have been carried out to utilize frequencies in the range from a microwave of 1 to 30 GHz to a millimeter wave of 30 to 300 GHz, and an application system using a high frequency signal of a millimeter wave, such as an inter-vehicular radar, is also proposed.

In such a high frequency system, there is a problem that since the frequency of a high frequency signal is high, the attenuation of the high frequency signal in a high frequency line constituting a circuit becomes large. For example, in the case where the high frequency line has a microstrip line structure, dielectric loss in a dielectric substrate becomes large in proportion to a frequency (when dielectric loss tangent is independent of a frequency), and conductor loss in the line conductor becomes large in proportion to a square root of the frequency. From this, even when the same microstrip line is used, when the frequency to be used becomes high from 1 GHz to 10 GHz, the dielectric loss becomes 10 times as high, and the conductor loss becomes about 3.2 times as high, and there is a problem that in order to compensate the loss, it becomes necessary to heavily use expensive high frequency components having low noise, high efficiency and high gain, and the system becomes expensive.

It is known that as compared with the high frequency line of the microstrip line structure as stated above, the transmission loss of a high frequency signal in a waveguide is low. For example, the loss of a waveguide WR-28 used in a band of 26 GHz to 40 GHz is about 0.005 dB/cm at 40 GHz, and this is remarkably smaller than the loss of about 1 dB/cm of the microstrip line using an aluminum substrate. This is because as compared with the normal high frequency line (generally designed to have an impedance of 50.OMEGA.) by the microstrip line or the like, the impedance of the waveguide is high (although changed according to the frequency, it is designed to be of the order of approximately 500.OMEGA.), and in the normal high frequency line, although the contribution of electric field energy transmitted in the dielectric substance is large in relation to the transmitted signal energy, the waveguide has such a structure that air having a dielectric loss tangent of almost 0 is used as the dielectric substance, a current flowing through the wall of the waveguide, which causes relatively low magnetic energy, may be small, and since the current flows through a relatively wide area of the wall of the waveguide, electric resistance becomes small and the conductor loss becomes small.

Besides, waveguides are generally connected to each other by screws. Thus, attachment and detachment can be easily performed. For example, when the waveguide is used for the connection of a high frequency circuit module and an antenna, their respective waveguide ports are used to carry out their respective checks before assembly, and a high frequency front end can be assembled by combining good components with each other, and the manufacture yield can be raised. From these, the front end using the waveguide is conventionally often adopted for transmission between the high frequency circuit module and the antenna, in which a transmission distance often becomes long.

FIG. 14 is a sectional view for explaining a structure of such a high frequency front end. According to FIG. 14, a front end 10 is constructed such that a module 11 and an antenna 12 are connected through a waveguide member 13. The module 11 is mounted on a metal chassis 15 having a waveguide opening 14. Besides, in this front end 10, there is constructed a high frequency line-to-waveguide converter 18 including a microstrip substrate 16 in which a microstrip line as a high frequency line is formed and a waveguide constituted by the waveguide opening 14 and a short circuit termination member 17. A wiring substrate 19 on which a high frequency component is mounted is connected to the microstrip line of the microstrip substrate 16 by wire bonding.

The high frequency line-to-waveguide converter 18 in this front end 10 is of the type in which at a position apart from the short circuit termination surface of the short circuit termination member 17 by a distance of 1/4 of a wavelength (guide wavelength), in the waveguide, of an electromagnetic wave excited by a high frequency signal, a probe (a portion where although a line conductor is extended, a ground conductor is not formed) formed on the microstrip substrate 16 is inserted from the side of the waveguide by a length of approximately 1/4 of a signal wavelength. This probe functions as an antenna in the waveguide, and radiates a high frequency signal as an electromagnetic wave into the waveguide. The half of the electromagnetic wave radiated into the waveguide is directly transmitted to the lower waveguide member 13, and the remaining half is transmitted toward the upper short circuit termination member 17. The phase of the electromagnetic wave transmitted toward the short circuit termination member 17 is inverted at the short circuit termination surface and is totally reflected. The totally reflected electromagnetic wave is returned to the probe portion, and is combined with the electromagnetic wave directly radiated downward from the probe. At this time, when the distance between the probe and the short circuit termination surface is made 1/4 of the guide wavelength, the length of the both way optical path starting from the probe and returning to the probe via the short circuit termination surface becomes the 1/2 wavelength, and the phase of the electromagnetic wave reflected at the short circuit termination surface becomes opposite to that of the electromagnetic wave directly radiated from the probe by the optical path difference. Eventually, the phase of the electromagnetic wave reflected at the short circuit termination surface is inverted when it is reflected at the short circuit termination surface, and further, the phase is reversed by the optical path difference, and becomes the same as the phase of the electromagnetic wave directly radiated downward from the probe, and the electromagnetic wave is transmitted to the lower waveguide member 13.

At this time, in order to cause the probe to function as the antenna, the length of the probe inserted into the waveguide is required to be made exactly 1/4 of the wavelength of the transmission line. Besides, in order to cause the phase of the electromagnetic wave radiated from the probe upward and reflected at the short circuit termination surface to become the same phase as the phase of the electromagnetic wave radiated downward from the probe, the distance between the probe and the short circuit termination surface is required to be made exactly 1/4 of the guide wavelength. Accordingly, the characteristic is greatly changed by the insertion position of the microstrip substrate 16, which functions as the antenna, into the waveguide, and the relation between the position of the microstrip substrate 16 and the position of the short circuit termination surface of the short circuit termination member 17.

Since the high frequency line-to-waveguide converter 18, together with the wiring substrate 19, is constructed on the metal chassis 15 by assembly, there is a problem that in the case where conversion loss of the high frequency line-to-waveguide converter becomes large by position shift of the respective members, the assembly becomes poor, and all of the used members become wasteful. Besides, the related art is disclosed in WO96/27913 and Japanese Unexamined Patent Publication JP-A 2001-177312 (2001).

FIG. 15 is a sectional view for explaining a structure of a high frequency line-to-waveguide converter. According to FIG. 15, a front end 20 is constructed such that a high frequency package 21 is connected to an antenna 22 through a waveguide 23. The high frequency package 21 is constructed such that a conversion substrate 26 having a built-in waveguide converter 25 is joined to a metal base 24. The waveguide converter 25 converts a plane circuit 28 for transmitting a high frequency signal processed by a high frequency electronic component 27 mounted on the high frequency package 21 into a waveguide mode 31 through a slot 30 formed in a ground layer 29 in the inside of the conversion substrate 26.

In this high frequency package 21, it is necessary to provide the area for mounting of the high frequency electronic component 27, together with the waveguide converter 25, in the conversion substrate 26, and there is a problem that in the case where the number of parts of the high frequency electronic component 27 is increased, the size becomes large, and warp or fracture can occur due to the mismatch in thermal expansion between the conversion substrate 26 and the metal base 24 at the time of assembly of the package. Besides, the related art is disclosed in U.S. Pat. No. 6,239,669.

In order to solve the problem as stated above, for example, WO96/27913 proposes a microstrip-waveguide transition including a microstrip line formed on an upper surface of a dielectric substrate and a slot formed in a lower ground conductor layer and functioning as an antenna. In the microstrip-waveguide transition proposed by WO96/27913, the thickness of the dielectric substance from the slot to a waveguide is made 1/4 of a signal wavelength of a high frequency signal. This is such that a difference in impedance between the slot and the waveguide is adjusted by a 1/4 wavelength matching device of the dielectric substance.

According to this structure, an electromagnetic wave radiated from the slot and reflected at a boundary between the matching device of the dielectric substance and the waveguide is reflected at the ground conductor layer in which the slot is formed, and is again returned to the boundary between the matching device and the waveguide. At this time, when the thickness of the matching device is made 1/4 of the signal wavelength, an optical path difference between the electromagnetic wave (reflected wave), which is reflected at the boundary and is again returned, and the electromagnetic wave (direct wave) directly transmitted from the slot to the boundary becomes 1/2 of the signal wavelength, and the phase is inverted when the reflected wave is reflected at the ground conductor layer, and accordingly, the direct wave and the reflected wave have the same phase at the boundary to intensify each other, and are transmitted to the waveguide.

According to this conversion structure, although the conversion characteristic is greatly changed by the thickness of the matching device, in this case, since the matching device is integrally constructed in the dielectric substrate, it becomes possible to lessen variation in the thickness of the dielectric substance, and variation in the conversion characteristic can be made small. Besides, when the dielectric substrate at the microstrip side is covered with a cap, it also becomes possible to airtightly seal the microstrip side at the same time as the conversion into the waveguide.

In this structure, electromagnetic coupling between different layers is used for coupling of the high frequency line and the slot. This electromagnetic coupling, together with the foregoing matching device, plays a main role in the conversion operation. However, the characteristic of the electromagnetic coupling is changed by the size of the slot and the length of a stub (a portion where the high frequency line protrudes from the slot), that is, the relative positional relation between the high frequency line and the slot. Accordingly, in this structure, the conversion characteristic is greatly changed by the size of the slot and the length of the stub, and since the high frequency line and the slot are disposed in the different layers, there is a problem that the length of the stub determined from the relative positional relation between both is apt to vary, and the conversion characteristic is apt to change.

Besides, in this structure, since the slot is placed in the inside of the dielectric substrate, there is a problem that it is difficult to check the length of the slot, the width of the slot, and the length of the stub from the outside, and it is also difficult to stabilize the characteristic by making a check.

In order to solve the problem as stated above, for example, a high frequency line-to-waveguide converter is conceivable in which a slot functioning as an antenna is formed at a tip of a coplanar line on a surface of a dielectric substrate, a waveguide is connected to a rear surface of the dielectric substrate at a position opposite to the slot, and a shield conductor part for connecting the waveguide and a ground conductor layer of the coplanar line is provided along an opening of the waveguide. The coplanar line is constituted by a line conductor and ground conductor layers disposed at both sides thereof, and the ground conductor layers in this case function as the ground of the coplanar line, and further function also as reflecting plates for again reflecting an electromagnetic wave (reflected wave) radiated from the slot, reflected at the boundary between the dielectric substrate and the waveguide and returned to the slot side. According to this converter, when the distance from the slot to the boundary between the dielectric substrate and the waveguide is set to 1/4 of the wavelength of the electromagnetic wave transmitted through the dielectric layer, an optical path difference between the reflected wave, which is radiated from the slot, is reflected at the boundary between the dielectric substrate and the waveguide, is again reflected at the ground conductor layer and reaches the boundary, and the electromagnetic wave (direct wave) directly transmitted to the boundary from the slot becomes equal to 1/2 of the wavelength of the electromagnetic wave, and the phase of the magnetic field of the reflected wave is inverted when it is reflected at the boundary between the dielectric substrate and the waveguide, and accordingly, the direct wave and the reflected wave have the same phase at the boundary to intensify each other, and are transmitted to the waveguide. That is, the dielectric substrate intervening between the slot and the waveguide and having the thickness set to 1/4 of the wavelength of the electromagnetic wave functions as a matching device of the slot and the waveguide whose impedances are different from each other.

However, in this structure, since the coplanar line is in contact with the matching device of the dielectric substrate, part of the electromagnetic wave of the signal transmitted through the coplanar line is distributed in the matching device, and this generates an unnecessary electromagnetic wave distribution (here, called a mode) in the matching device, and there is a fear that the transmission of the high frequency signal to the waveguide is impeded. For example, immediately under the line conductor of the coplanar line, the magnetic field by the signal becomes parallel to the surface of the dielectric substrate. This magnetic field excites a TM mode as a resonant mode at the time when the matching device is made the dielectric waveguide, and the signal energy of a TE mode as a transmission mode shifts to the TM mode and resonates, and the signal is reflected, and accordingly, there is a case where the conversion into the waveguide can not be excellently performed.

In order to solve the problem as stated above, it is conceivable that for example, the conversion substrate 26 including only the waveguide converter 25 is fabricated, and is connected to the metal base 24. By doing so, it becomes possible to lessen the conversion substrate 26, the residual stress after the assembly due to the mismatch in thermal expansion between the conversion substrate 26 and the metal base 24 becomes low, and it is possible to prevent the warp or fracture of the high frequency package 21.

However, in this structure, when the upper surface of the conversion board 26 and the upper surface of the high frequency electronic component 27 are made the same surface, although the respective signal lines can be connected by wire bonding or ribbon bonding at a relatively short distance, since the thickness of the conversion substrate 26 including the waveguide converter 25 is generally overwhelmingly thicker than the thickness of the high frequency electronic component 27 used in the microwave or millimeter wave range, a connection distance between grounds at the respective lower surfaces becomes longer than a connection between signal conductors, and there is a case where the phase of the electric potential of the signal conductor deviates from the phase of the electric potential of the ground conductor at the connection part, and the high frequency signal can not be excellently transmitted.

SUMMARY OF THE INVENTION

The invention has been made in view of the foregoing problems, and an object thereof is to provide a high frequency line-to-waveguide converter which has a high conversion efficiency and a small variation in conversion characteristic.

Another object of the invention is to provide a high frequency line-to-waveguide converter in which an unnecessary mode does not easily occur and a conversion efficiency is high.

Still another object of the invention is to provide a high frequency package in which a conversion substrate including only a waveguide converter 65 is connected to a metal base to prevent a warp or a crack of the high frequency package, and transmission of a high frequency signal at a connection part between the conversion substrate and a high frequency electronic component is excellent.

The invention provides a high frequency line-to-waveguide converter comprising:

a high frequency line including a dielectric layer, a line conductor disposed on one surface of the dielectric layer, and a ground conductor layer disposed on the same surface so as to surround one end of the line conductor;

a slot formed in the ground conductor layer so as to be substantially orthogonal to the one end of the line conductor and coupled to the high frequency line;

a shield conductor part disposed on a side of or in an inside of the dielectric layer so as to surround the one end of the line conductor and the slot; and

a waveguide disposed on a side of the other surface of the dielectric layer so that an opening is opposite to the one end of the line conductor and the slot, and electrically connected to the shield conductor part.

According to the invention, since the high frequency line including the line conductor disposed on the one surface of the dielectric layer and the ground conductor layer disposed on the same surface so as to surround the one end of the line conductor is coupled to the slot formed in the ground conductor layer to be substantially orthogonal to the one end of the line conductor the high frequency line and the slot are formed on the same surface, and as a result, the relative positional relation of both is difficult to change, and variation in the length of a stub as a protruding portion of the high frequency line with respect to the slot can be made small, and accordingly, variation in the characteristic of electromagnetic coupling can be made small, and variation in the conversion characteristic of the high frequency line-to-waveguide conversion can be made small.

Besides, in the invention it is preferable that the shield conductor part includes a plurality of shield through conductors disposed in the inside of the dielectric layer.

According to the invention, when the shield conductor part includes the plurality of shield through conductors disposed in the inside of the dielectric layer, at the time of fabrication of the high frequency line-to-waveguide converter, the shield through conductors can be formed at the same time as the line conductor and the ground conductor layer, and the high frequency line-to-waveguide converter can be easily fabricated. Besides, since the shape of the region surrounded by the shield through conductors of the dielectric layer can be designed arbitrarily, for example, in the case where an unnecessary resonance occurs in the region surrounded by the shield through conductors of the dielectric layer, it becomes possible to shift the unnecessary resonance to the outside of the band of signal conversion by adjusting the arrangement of the shield conductor part.

Besides, in the invention it is preferable that a thickness of the dielectric layer is approximately (2n-1)/4 (n is a natural number) of a wavelength of a signal transmitted through the high frequency line.

According to the invention, when the thickness of the dielectric layer is approximately 1/4 of the wavelength of the signal transmitted through the high frequency line, a distance from the slot to the boundary between the dielectric layer and the waveguide becomes approximately 1/4 of the signal wavelength, an optical path difference between a reflected wave, which is radiated from the slot, is reflected at the boundary between the dielectric layer and the wave guide, is again reflected at the ground conductor layer in which the slot is formed, and is again returned to the boundary and a direct wave directly transmitted from the slot to the boundary becomes 1/2 of the signal wavelength, and the phase is inverted when the reflected wave is reflected at the ground conductor layer, and accordingly, the direct wave and the reflected wave come to have the same phase at the boundary to intensify each other, and the signal is efficiently transmitted to the waveguide. At this time, when the thickness of the dielectric layer is made (2n-1)/4 of the signal wavelength, where n is a natural number, the optical path difference between the reflected wave and the direct wave becomes (n-1)/2 of the signal wavelength, and since the optical path difference n times as long as the signal wavelength is equivalent to a case where there is no optical path difference, it substantially becomes 1/2 of the signal wavelength, and the same effect is obtained.

Besides, according to the invention, when the thickness of the dielectric layer is approximately (2n-1)/4 of the wavelength of the signal transmitted through the high frequency line, where n is a natural number, the distance from the slot to the boundary between the dielectric layer and the waveguide becomes approximately (2n-1)/4 of the signal wavelength, and since the length of the optical path in which the reflected wave reflected at the boundary between the dielectric layer and the waveguide is totally reflected at the ground conductor layer and is returned to the boundary becomes substantially 1/2 of the signal wavelength, the phase becomes inverted when the wave is returned, and in combination with the phase inversion by the total reflection at the ground conductor layer, the reflected wave comes to have the same phase as the direct wave directly transmitted from the slot to the boundary, and these are combined with each other and the signal is efficiently transmitted to the waveguide. Besides, in addition to that, the signal frequency becomes high, and the signal wavelength becomes short, and in the case where the strength of the dielectric layer is lowered when the thickness of the dielectric layer is set to 1/4 of the signal wavelength, it becomes possible to suppress the lowering of the strength of the dielectric layer by setting the thickness of the dielectric layer to 3/4, 5/4 or the like of the signal wavelength.

Besides, in the invention it is preferable that a tip of the one end of the line conductor is opened, and a distance between the tip and the slot is approximately (2n-1)/4 (n is a natural number) of the wavelength of the signal transmitted through the high frequency line.

According to the invention, when the tip of the one end of the line conductor is opened, and the distance between the tip and the slot is approximately 1/4 of the wavelength of the signal transmitted through the high frequency line, the signal (traveling wave) transmitted through the high frequency line is totally reflected at the open end, and becomes a regressive wave transmitted in the opposite direction. At this time, since the tip is opened, a current can not flow in the tip, and the current of the regressive wave is reflected in this portion while the phase is inverted to cancel the current of the traveling wave. The synthesis of the current of the traveling wave and the current of the regressive wave which inverts the phase produces a standing wave in which the open tip is a node and a node pitch is 1/2 of the signal wavelength. Here, since the distance between the open tip and the slot is 1/4 of the signal wavelength, a portion of the high frequency line just above the slot becomes the antinode of the standing wave, the current becomes maximum, and the magnetic field generated by the current becomes maximum. The magnetic field which becomes maximum moves to the slot, excellent electromagnetic coupling is performed, and the signal is finally efficiently transmitted to the waveguide. At this time, when the distance between the open end and the slot is made (2n-1)/4 of the signal wavelength, where n is a natural number, the slot is positioned at the position of the antinode of the standing wave formed by synthesis of the traveling wave and the regressive wave, and the same effect as the case where the distance between the open end and the slot is 1/4 of the signal wavelength is obtained.

Besides, according to the invention, when the tip of the high frequency line is opened, and the distance between the open tip and the slot is set to (2n-1)/4 of the signal wavelength, where n is a natural number, the standing wave formed by synthesis of the traveling wave transmitted through the high frequency line and the regressive wave reflected at the open tip can be made such that the magnetic field becomes highest at the portion of the slot, and the electromagnetic coupling from the high frequency line to the slot through the magnetic field is most excellently performed, and accordingly, the conversion efficiency of the high frequency line-to-waveguide conversion can be made high.

Besides, in the invention it is preferable that a tip of the one end of the line conductor is short circuited to the ground conductor layer, and a distance between the tip and the slot is approximately (n-1)/2 (n is a natural number) of the wavelength of the signal transmitted through the high frequency line.

According to the invention, when the tip of the one end of the line conductor is short-circuited to the ground conductor layer, and the distance between the tip and the slot is approximately 1/2 of the wavelength of the signal transmitted through the high frequency line, the signal (traveling wave) transmitted through the high frequency line is totally reflected at the short-circuit end, and becomes the regressive wave transmitted in the opposite direction. At this time, since the tip is short-circuited, a maximum current flows in the tip part, and in this portion, the current of the regressive wave is reflected at the same phase as the current of the traveling wave. The synthesis of the current of the traveling wave and the current of the regressive wave which does not change the phase produces a standing wave in which the open tip is an antinode and an antinode pitch is 1/2 of the signal wavelength. Here, since the distance between the short-circuit tip and the slot is 1/2 of the signal wavelength, a portion of the high frequency line just above the slot becomes the antinode of the standing wave, the current becomes maximum, and the magnetic field generated by the current becomes maximum. The maximum magnetic field moves to the slot, excellent electromagnetic coupling is performed, and the signal is finally efficiently transmitted to the waveguide. At this time, when the distance between the short-circuit tip and the slot is made (n-1)/2 of the signal wavelength, where n is a natural number, the slot is positioned at the position of the antinode of the standing wave formed by synthesis of the traveling wave and the regressive wave, and the same effect as the case where the distance between the short-circuit tip and the slot is 1/2 of the signal wavelength is obtained.

Besides, according to the invention, when the tip of the high frequency line conductor is short-circuited by the ground conductor layer, and the distance between the short-circuited tip and the slot is set to (n-1)/2 of the signal wavelength, where n is a natural number, the standing wave formed by synthesis of the traveling wave transmitted through the high frequency line and the regressive wave reflected at the short-circuited tip can be made such that the magnetic field becomes highest at the portion of the slot, and the electromagnetic coupling from the high frequency line to the slot through the magnetic field is most excellently performed, and accordingly, the conversion efficiency of the high frequency line-to-waveguide conversion can be raised.

The invention provides a high frequency line-to-waveguide converter comprising:

a high frequency line including a dielectric layer, a line conductor disposed on one surface of the dielectric layer, and a same surface ground conductor layer disposed on the same surface so as to surround one end of the line conductor;

a slot formed in the same surface ground conductor layer so as to be substantially orthogonal to the one end of the line conductor and coupled to the high frequency line in terms of high frequency;

a shield conductor part disposed on a side of or in an inside of the dielectric layer so as to surround the one end of the line conductor and the slot;

a waveguide disposed on a side of the other surface of the dielectric layer so that an opening is opposite to the one end of the line conductor and the slot, and electrically connected to the shield conductor part; and

an internal ground conductor layer disposed in the inside of the dielectric layer between the same surface ground conductor layer and the waveguide and having a transmission opening for causing an electromagnetic wave of a signal transmitted through the high frequency line to be transmitted between the slot and the waveguide.

According to the invention, in a portion of the dielectric layer surrounded by the same surface ground conductor layer disposed on the same surface so as to surround the line conductor disposed on the one surface of the dielectric layer and the one end of the line conductor, the shield conductor part disposed on the side of or in the inside of the dielectric layer so as to surround the slot, and the waveguide opening part at the side of the other surface of the dielectric layer, and in a portion along the waveguide opening having a highest magnetic field of a TM mode as a resonant mode, since the high frequency line part and the waveguide opening part are separated by the internal ground conductor layer, an electromagnetic mode transmitted from the high frequency line to the waveguide is not coupled with the TM mode as the resonant mode, and as a result, a signal energy transmitted through the high frequency line is not transferred to the resonant mode, and signal reflection by resonance is made to difficult to generate, so that excellent signal conversion from the high frequency line to the waveguide can be performed.

Besides, in the invention it is preferable a distance between the internal ground conductor layer and the opening of the waveguide is approximately (2n-1)/4 (n is a natural number) of a wavelength of an electromagnetic wave of a signal transmitted through the high frequency line.

According to the invention, when the distance between the internal ground conductor layer and the waveguide is approximately 1/4 of the wavelength of the electromagnetic wave excited in the dielectric layer by the signal transmitted through the high frequency line, an optical path difference between a reflected wave, which is radiated from the slot, is reflected at the boundary between the dielectric layer and the waveguide, is again reflected at the internal ground conductor layer, and is again returned to the boundary between the dielectric layer and the waveguide, and a direct wave directly transmitted from the slot to the boundary between the dielectric layer and the waveguide becomes approximately 1/2 of the wavelength of the electromagnetic wave excited in the dielectric layer by the signal, and further, the phase of the magnetic field is inverted when the reflected wave is reflected at the boundary between the dielectric layer and the waveguide, and accordingly, the direct wave and the reflected wave have the same phase at the boundary between the dielectric layer and the waveguide to intensify each other, and the electromagnetic wave signal is efficiently transmitted to the waveguide. At this time, when the distance between the internal ground conductor layer and the waveguide is made approximately (2n-1)/4 of the wavelength of the electromagnetic wave excited in the dielectric layer by the signal, where n is a natural number, the optical path difference between the reflected wave and the direct wave becomes approximately (2n-1)/2 of the wavelength of the electromagnetic wave, and the same effect as the case where the optical path difference between the reflected wave and the direct wave is approximately 1/2 of the wavelength of the electromagnetic wave is obtained.

Besides, in the invention it is preferable that an area of the transmission opening is half or less of an area of a region surrounded by the shield conductor part.

According to the invention, the area of the transmission opening is the half or less of the area of the region surrounded by the shield conductor part, and as a result, the internal ground conductor layer occupies the half or more of the area surrounded by the shield conductor part, so that the half or more of the reflected wave radiated from the slot and reflected at the boundary between the dielectric layer and the waveguide is again reflected at the internal ground conductor layer, the reflected wave and the direct wave from the slot intensify each other, and the conversion efficiency of the high frequency line-to-waveguide conversion can be raised.

Besides, in the invention it is preferable that the shield conductor part includes a plurality of shield through conductors disposed in the inside of the dielectric layer.

According to the invention, the shield conductor part includes the plurality of shield through conductors disposed in the inside of the dielectric layer, and when the high frequency line-to-waveguide converter is fabricated, these through conductors can be formed at the same time as the line conductor, the ground conductor layer, and the internal ground conductor layer, and the high frequency line-to-waveguide converter can be easily fabricated.

Besides, in the invention it is preferable that a tip of the one end of the line conductor is opened, and a distance between the tip and the slot is approximately (2n-1)/4 (n is a natural number) of the wavelength of the signal transmitted through the high frequency line.

According to the invention, in the case where the tip of the high frequency line conductor is opened, and the distance between the open tip and the slot is approximately 1/4 of the signal wavelength, an optical path length of the high frequency signal transmitted to the open tip from the slot, totally reflected at the open tip, and returned to the slot becomes approximately 1/2 of the signal wavelength, and the phase of the magnetic field is inverted by the total reflection at the open tip, and accordingly, the returned high frequency signal comes to have the same phase as the high frequency signal transmitted through the high frequency line, and they intensify each other, and are firmly coupled with the slot, and the conversion efficiency from the high frequency line to the waveguide can be raised. At this time, when the distance between the open tip and the slot is made approximately (2n-1)/4 of the signal wavelength, where n is a natural number, the optical path difference between the reflected wave and the direct wave becomes approximately (2n-1)/2 of the signal wavelength, and the same effect as the case where the optical path difference between the reflected wave and the direct wave is approximately 1/2 of the wavelength of the electromagnetic wave is obtained.

Besides, in the invention it is preferable that a tip of the one end part of the line conductor is short-circuited to the same surface ground conductor layer, and the distance between the tip and the slot is approximately (n-1)/2 (n is a natural number) of the wavelength of the signal transmitted through the high frequency line.

According to the invention, in the case where the tip of the line conductor of the high frequency line is short-circuited and the distance between the short-circuit tip and the slot becomes approximately 1/2 of the signal wavelength, an optical path length of the high frequency signal transmitted from the slot to the short-circuit tip, totally reflected at the short-circuit tip, and returned to the slot comes to have substantially the same length as the signal wavelength, and since the phase of the magnetic field is not changed in the total reflection at the short-circuit tip, the returned high frequency signal comes to have the same phase as the high frequency signal transmitted through the high frequency line, and they intensify each other and are firmly coupled with the slot, and the conversion efficiency from the high frequency line to waveguide can be raised. At this time, when the distance between the short-circuit tip and the slot is made approximately (n-1)/2 of the signal wavelength, where n is a natural number, the high frequency signal transmitted from the slot to the short-circuit tip, totally reflected at the short-circuit tip, and returned to the slot comes to have the same phase as the high frequency signal transmitted through the high frequency line, and they intensify each other and are firmly coupled with the slot, and the conversion efficiency from the high frequency line to the waveguide can be raised. Besides, in the case where n is 1, the line conductor is short-circuited at the slot part, and since the reflection by the short circuit does not change the phase of the magnetic field, it comes to have the same phase as the high frequency signal transmitted through the high frequency line, and they intensify each other.

Besides, in the invention it is preferable that the same surface ground conductor layer and the internal ground conductor layer are connected by a connection conductor disposed to pass through the dielectric layer along the transmission opening.

According to the invention, the ground conductor layer of the high frequency line and the internal ground conductor layer are connected by the connection conductor along the transmission opening, and it becomes possible to effectively use a high frequency line portion outside of the region surrounded by the connection conductor, and as a result, a system using the high frequency line-to-waveguide converter can be miniaturized.

In the invention, it is preferable that a second dielectric layer is laminated on the dielectric layer, and a one surface ground conductor layer is provided on one surface of the second dielectric layer so as to cover the line conductor, whereby a coplanar line structure having ground is achieved.

The invention provides a high frequency package, wherein a through hole is formed in a metal base having a mounting part of a high frequency electronic component on one surface, the through hole being disposed to be adjacent to the mounting part and having an opening connected with a waveguide on a side of another surface, a connection terminal part including a high frequency line conductor directed from an outer peripheral part to a center part on one surface of a dielectric substrate and a same surface ground conductor disposed to be close to the high frequency line conductor is formed on one side of the through hole, a frame ground conductor having a shape conforming to an opening of the through hole on the one side is formed on another surface of the dielectric substrate so as to be opposite to an end of the high frequency line conductor on a side of the center part, an internal ground conductor provided with a slot coupled with the end of the high frequency line conductor at the side of the center part in terms of high frequency is formed between the end of the high frequency line conductor at the side of the center part in the inside of the dielectric substrate and the frame ground conductor, and a conversion substrate in which the same surface ground conductor is connected to the internal ground conductor through a first connection conductor and the frame ground conductor is connected to the internal ground conductor through a second connection conductor, is jointed on the one side of the through hole such that the connection terminal part is positioned on a side of the mounting part and the frame ground conductor is made to conform to the opening of the through hole on the one side.

The invention provides a high frequency package comprising:

a metal base including a mounting part for a high frequency electronic component on one surface thereof, a through hole disposed to be adjacent to the mounting part and having an opening on another side thereof connected with a waveguide, being formed therein; and

a conversion substrate, including:

a dielectric substrate,

a connection terminal part, including a high frequency line conductor disposed so as to extend from an outer peripheral part toward a center part on one surface of the dielectric substrate, and a same surface ground conductor disposed to be close to the high frequency line conductor on the one surface of the dielectric substrate,

a frame ground conductor formed on another surface of the dielectric substrate in a shape conforming to an opening on one side of the through hole so as to be opposite to an end of the high frequency line conductor on the center part side,

an internal ground conductor formed in an inside of the dielectric substrate and between the end of the high frequency line conductor on the center part side and the frame ground conductor, the internal ground conductor being provided with a slot coupled to the end of the high frequency line conductor on the center part side in terms of high frequency,

a first connection conductor for connecting the same surface ground conductor and the internal ground conductor, and

a second connection conductor for connecting the frame ground conductor and the internal ground conductor,

wherein the conversion substrate is jointed on the one side of the through hole of the metal base such that the connection terminal part is positioned on the side of the mounting part of the metal base and the frame ground conductor is made to conform to the opening on the one side of the through hole of the metal base.

According to the invention, since the connection terminal part is formed which is disposed to be adjacent to the mounting part of the high frequency electronic component and includes the high frequency line conductor directed from the outer peripheral part to the center part on the one surface of the dielectric substrate and the same surface ground conductor disposed to be close to the high frequency line conductor, when the high frequency line conductors of the conversion substrate and the high frequency electronic component and the same surface ground conductors of these are respectively connected to each other by wire bonding, the connection distance between the high frequency line conductors can be made substantially equal to the connection distance between the same surface ground conductors, and the high frequency package can be provided in which the phases of the high frequency signal and the ground potential at the connection part between the conversion substrate and the high frequency electronic component are not delayed and the signal transmission is excellent.

Besides, the invention provides a high frequency package, wherein a through hole is formed in a metal base having a mounting part of a high frequency electronic component on one surface, the through hole being disposed to be adjacent to the mounting part and having an opening connected with a waveguide on a side of another surface, a connection terminal part including a high frequency line conductor directed from an outer peripheral part to a center part on one surface of a dielectric substrate and a same surface ground conductor disposed on the same surface so as to surround an end of the high frequency line conductor on a side of the center part is formed on one side of the through hole, a frame ground conductor having a shape conforming to an opening of the through hole on the one side is formed on the other surface of the dielectric substrate so as to be opposite to the end of the high frequency line conductor at the side of the center part, a slot formed to be orthogonal to the end of the high frequency line conductor at the side of the center part and coupled to the high frequency line conductor in terms of high frequency is provided in the same surface ground conductor, and a conversion substrate in which the same surface ground conductor is connected to the frame ground conductor through a connection conductor is joined on the one side of the through hole such that the connection terminal part is positioned on a side of the mounting part and the frame ground conductor is made to conform to the opening of the through hole on the one side.

The invention provides a A high frequency package comprising:

a metal base a metal base having a mounting part of a high frequency electronic component on one surface, and a through hole disposed to be adjacent to the mounting part, an opening on one side of the through hole being connected with a waveguide; and

a high frequency line-to-waveguide conversion substrate joined on an opening on another side of the through hole, the high frequency line-to-waveguide conversion substrate including:

a high frequency line including: a dielectric substrate; a high frequency line conductor directed from an outer peripheral part to a center part on one surface of the dielectric substrate; and a same surface ground conductor disposed on the same surface as the one surface of the dielectric substrate so as to surround an end of the high frequency line conductor on the center part side,

a frame ground conductor formed on another surface of the dielectric substrate in a shape conforming to an opening on another side of the through hole so as to be opposite to the end of the high frequency line conductor on the center part side;

a slot provided on the same surface ground conductor and formed to be orthogonal to the end of the high frequency line conductor on the center part side and coupled to the high frequency line in terms of high frequency; and

a connection conductor for connecting the same surface ground conductor and the frame ground conductors,

wherein the high frequency line-to-waveguide conversion substrate is joined on the other side of the through hole such that the high frequency line is positioned on a side of the mounting part and the frame ground conductor is made to conform to the opening on the other side of the through hole.

The invention provides a high frequency package comprising:

a metal base including a mounting part for a high frequency electric component on one surface thereof, a through hole disposed to be adjacent to the mounting part and having the lower side opening connected with the waveguide, being formed therein; and

a conversion substrate, including:

a diel