Title: Nonreciprocal circuit element with notch part in yoke
Abstract: Provided is a nonreciprocal circuit element which has increased lengths of central conductors to be compatible with miniaturization while exhibiting superior performance. In the nonreciprocal circuit element, a first yoke has a rectangular upper plate, a pair of side plates bent downward from sides of the upper plate facing each other, and notch parts formed at the central portion of the pair of side plates. Ends of a magnet are placed within the notch parts. Thus, the magnet can be enlarged and a ferrite member provided corresponding thereto can also be enlarged. Accordingly, the lengths of conductors of central conductors mounted on the ferrite member are increased, thereby achieving high performance while not adversely affecting miniaturization.
Patent Number: 6,977,559 Issued on 12/20/2005 to Shimizu, et al.
| Inventors:
|
Shimizu; Yuichi (Fukushima-ken, JP);
Shibayama; Takamitsu (Fukushima-ken, JP);
Komai; Eiichi (Niigata-ken, JP)
|
| Assignee:
|
Alps Electric Co., Ltd. (Tokyo, JP)
|
| Appl. No.:
|
842896 |
| Filed:
|
May 10, 2004 |
Foreign Application Priority Data
| May 14, 2003[JP] | 2003-135300 |
| Current U.S. Class: |
333/1.1; 333/24.2 |
| Intern'l Class: |
H01P 001/38.3 |
| Field of Search: |
333/11,242
|
References Cited [Referenced By]
U.S. Patent Documents
Primary Examiner: Jones; Stephen E.
Attorney, Agent or Firm: Brinks Hofer Gilson & Lione
Claims
1. A nonreciprocal circuit element comprising:
a flat ferrite member;
first, second and third central conductors disposed on the ferrite member such
that the first, second and third central conductors are disposed on surfaces different
in a vertical direction with a dielectric element interposed therebetween, and
parts thereof intersecting one another in the vertical direction;
a magnet disposed on the central conductors;
a first yoke disposed so as to cover a top surface of the magnet; and
a second yoke forming a closed magnetic circuit in combination with the first
yoke, the second yoke being disposed below the ferrite member;
wherein the first yoke has a rectangular upper plate, a pair of side plates bent
downward from at least sides of the upper plate facing each other, and notch parts
formed in a central portion of the pair of side plates, and respective ends of
the magnet are placed within the notch parts.
2. The nonreciprocal circuit element of claim 1, wherein ends of the ferrite
member are disposed in proximity to extension lines of the side plates.
3. The nonreciprocal circuit element of claim 1, wherein a bottom surface of
the magnet placed within the notch parts does not contact the side plates and the
second yoke.
4. The nonreciprocal circuit element of claim 1, wherein a resin case is provided
in the second yoke, the resin case having a first receiving portion in which the
ferrite member is accommodated, and a plurality of second receiving portions in
which a plurality of capacitors connected to the central conductors are accommodated.
5. The nonreciprocal circuit element of claim 1, wherein the first receiving
portion is arranged at a central portion of the resin case and the second receiving
portions are arranged at both sides of the first receiving portion along long sides
of the magnet and the ferrite member.
6. The nonreciprocal circuit element of claim 1, wherein the magnet has a quadrangular
shape having long sides and short sides, and ends of the short sides of the magnet
are placed within the notch parts.
7. The nonreciprocal circuit element of claim 6, wherein chamfers are formed
at corners of the magnet.
8. The nonreciprocal circuit element of claim 6, wherein the ferrite member has
a quadrangular shape having long sides and short sides, and in a state in which
the long sides of the magnet are joined to the long sides of the ferrite member
and the short sides of the magnet are joined to the short sides of the ferrite
member, respectively, a top surface of the ferrite member is disposed within the
dimension of the bottom surface of the magnet, and the short sides of the ferrite
member are disposed in proximity of extension lines of the side plates.
9. The nonreciprocal circuit element of claim 8, wherein chamfers are formed
at corners of the ferrite member.
Description
This application claims the benefit of priority to Japanese Patent Application
No. 2003-135300, herein incorporated by reference.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a nonreciprocal circuit element such as an isolator
or a circulator used for an antenna duplexer or the like.
2. Description of the Related Art
A conventional nonreciprocal circuit element will now be described with reference
to FIGS. 13 to 15, in which FIG. 13 is an exploded perspective view of a conventional
nonreciprocal circuit element, FIG. 14 is a plan view illustrating essential parts
of the conventional nonreciprocal circuit element, and FIG. 15 is a developed view
of a central conductor of the conventional nonreciprocal circuit element.
Referring to FIGS. 13 through 15, the conventional nonreciprocal circuit
element includes a first box-shaped yoke 51, a disk-shaped magnet 52
disposed in the first yoke 51, and a flat ferrite member 53 disposed
under the magnet 52. The conventional nonreciprocal circuit element further
includes three central conductors 54, 55 and 56 formed of
metal plates partly intersecting one another and mounted on the ferrite member
53 by being spaced apart from one another by an angle of 120 degrees, a
box-shaped resin case 57 accommodating the ferrite member 53, and
a second U-shaped yoke 58 disposed under the resin case 57.
The first box-shaped yoke 51 has a rectangular upper plate 51
a,
and four side plates 51
b bent downward from four sides of the upper
plate 51
a. A magnet 52 is arranged within the first yoke 51,
and its top surface is adhered to the inner surface of the upper plate 51
a
using an adhesive or the like.
The ferrite member 53 has a rectangular configuration in which two long
sides 53
a face each other and two short sides 53
b face
each other. The top surface of the ferrite member 53 is disposed to face
the magnet 52 within the effective range of the bottom surface of the magnet 52.
As shown in FIG. 15, first, second and third central conductors 54, 55
and 56 are formed by notching metal plates and extend outwardly from a square
ground portion 70 which is disposed in the center thereof.
Each of the first, second and third central conductors 54, 55
and 56 has two-divided conductors 54
a, 55
a and
56
a each having a slit formed in a vertical direction, and first,
second and third port portions 54
b, 55
b and 56
b
provided at ends of the conductors 54
a, 55
a and
56
a, respectively.
The first, second and third central conductors 54, 55 and 56
are configured such that the ground portion 70 is disposed under the ferrite
member 53. In such a state, the conductors 54
a, 55
a
and 56
a are bent along the side and top surfaces of the ferrite
member 53.
The first, second and third central conductors 54, 55 and 56
are disposed on the top surface of the ferrite member 53 in a vertical direction
in a state in which they are individually insulated from one another by insulators,
although not shown.
When the first, second and third central conductors 54, 55 and
56 are mounted on the ferrite member 53, the first and second central
conductors 54 and 55 are placed at the short sides 53
b
so as to traverse the longer surface of the ferrite member 53 while
the third central conductor 56 is placed at the long side 53
a
so as to traverse the shorter surface of the ferrite member 53 in a
state in which it is parallel to the short sides 53
b.
The resin case 57 has a bottom wall 57
b having a rectangular
hole 57
a at its central portion. The bottom wall 57
b has
concave portions 57
c formed along three sides of the hole 57
a.
The ferrite member 53 having the first, second and third central conductors
54, 55 and 56 mounted thereon is disposed within the hole
57
a, so that the ground portion 70 corresponding to one end
of each of the first, second and the third central conductors 54, 55
and 56 is connected to the second yoke 58.
Chip-type capacitors 62, 63 and 64 and a chip-type
resistor 65 are arranged within the concave portions 57 around the
hole 57
a, and lower electrodes of the capacitors 62, 63
and 64 and an electrode 65
a at one end of the resistor 65
are connected to the second yoke 58, respectively.
The respective port portions 54
c and 55
c of the first
and second central conductors 54 and 55 are connected to the upper
electrodes of the capacitors 62 and 63 by soldering, while the port
portion 56
c of the third central conductor 56 is connected
to the upper electrode of the capacitor 64 and to the top surface of the
electrode 65
b at the other end of the resistor 65 by soldering.
In other words, the capacitor 62 is disposed in one of long sides 53
a
of the ferrite member 53, and the capacitor 63 is disposed at
the short side 53
b perpendicular to the long side 53
a.
Also, the capacitor 64 and the resistor 65 are formed at the other
long side 53
a so as to surround the hole 57
a.
In a state in which the magnet 52, the ferrite member 53 and the
resin case 57 are interposed between the first and second yokes 51
and 58, the first and second yokes 51 and 58 are connected
with each other to form a closed magnetic circuit composed of the first and second
yokes 51 and 58, thereby completing the nonreciprocal circuit element,
as disclosed in U.S. Pat. No. 6,597,257.
However, since the magnet 52 of the conventional nonreciprocal circuit
element is accommodated in the box-shaped first yoke 51, it is necessary
to reduce the size of the magnet 52 and the ferrite member 53 provided
corresponding thereto.
As the nonreciprocal circuit element becomes smaller sized, the magnet 53
and the ferrite member 53 are further miniaturized accordingly. Consequently,
the lengths of the two-divided conductors 54
a, 55
a and
56
a of the first, second and third central conductors 54,
55 and 56 mounted on the ferrite member 53 are decreased,
resulting in deteriorating the performance of the nonreciprocal circuit element.
Also, since the capacitors 62, 63 and 64 and the resistor
65 are arranged in the vicinity of the hole 57
a including
the ferrite member 53, the ferrite member 53 reduces in size. Further,
since the lengths of the conductors 54
a, 55
a and 56
a
of the first, second and third central conductors 54, 55 and
56 reduce, the performance of the nonreciprocal circuit element may deteriorate.
SUMMARY OF THE INVENTION
Accordingly, an object of the present invention is to provide a nonreciprocal
circuit element which has increased lengths of central conductors to be compatible
with miniaturization while exhibiting superior performance.
To accomplish the above object, according to a first solving means of the present
invention, there is provided a nonreciprocal circuit element a flat ferrite member,
first, second and third central conductors disposed on the ferrite member such
that they are disposed on surfaces different in a vertical direction with a dielectric
element interposed therebetween, and parts thereof intersecting one another in
the vertical direction, a magnet disposed on the central conductors, a first yoke
disposed so as to cover the top surface of the magnet, and a second yoke forming
a closed magnetic circuit in combination with the first yoke, the second yoke being
disposed below the ferrite member, the first yoke has a rectangular upper plate,
a pair of side plates bent downward from at least sides of the upper plate facing
each other, and notch parts formed in the central portion of the pair of side plates,
and the respective ends of the magnet are placed within the notch parts.
According to second solving means of the present invention, the ends of
the ferrite member are disposed in proximity to extension lines of the side plates.
Also, according to third solving means of the present invention, the magnet
may have a quadrangular shape having long sides and short sides, and the ends of
the short sides of the magnet may be placed within the notch parts.
Further, according to forth solving means of the present invention, chamfers
may be formed at corners of the magnet.
Preferably, according to fifth solving means of the present invention,
the ferrite member has a quadrangular shape having long sides and short sides,
and in a state in which the long sides of the magnet are joined to the long sides
of the ferrite member and the short sides of the magnet are joined to the short
sides of the ferrite member, respectively, the top surface of the ferrite member
is disposed within the dimension of the bottom surface of the magnet, and the short
sides of the ferrite member are disposed in proximity of the extension lines of
the side plates.
In sixth solving means of the present invention, chamfers may be formed at corners
of the ferrite member.
As seventh solving means of the present invention, the bottom surface of the
magnet
placed within the notch parts does not contact with the side plates and the second yoke.
Further, as eighth solving means of the present invention, a resin case
may be provided in the second yoke, and the resin case has a first receiving portion
in which the ferrite member is accommodated, and a plurality of second receiving
portions in which a plurality of capacitors connected to the central conductors
are accommodated.
Preferably, as ninth solving means of the present invention, the first
receiving portion is arranged at the central portion of the resin case and the
second receiving portions are arranged at both sides of the first receiving portion
along the long sides of the magnet and the ferrite member.
BRIEF DESCRIPTION OF THE DRAWINGS
The above aspect and advantages of the present invention will become more apparent
by describing in detail preferred embodiments thereof with reference to the attached
drawings in which:
FIG. 1 is a plan view of a nonreciprocal circuit element according to the first
embodiment of the present invention;
FIG. 2 is a front view of the nonreciprocal circuit element according to the
first embodiment;
FIG. 3 is a side view of the nonreciprocal circuit element according to the
first embodiment;
FIG. 4 is a plan view of the nonreciprocal circuit element according to the
first embodiment in a state in which a first upper yoke is removed;
FIG. 5 is a plan view of the nonreciprocal circuit element according to the
first embodiment in a state in which a first yoke and a magnet are removed;
FIG. 6 is a cross-sectional view taken along the line 6—6
of FIG. 4;
FIG. 7 is a cross-sectional view taken along the line 7—7
of FIG. 4;
FIG. 8 is an exploded perspective view illustrating main parts of the nonreciprocal
circuit element according to the first embodiment;
FIG. 9 is a developed view of central conductors incorporated in the nonreciprocal
circuit element according to the first embodiment;
FIG. 10 is a plan view of a nonreciprocal circuit element according to a second
embodiment in a state in which an upper plate of a first yoke is removed;
FIG. 11 is a plan view of a nonreciprocal circuit element according to a third
embodiment in a state in which an upper plate of a first yoke is removed;
FIG. 12 is an equivalent circuit diagram of the nonreciprocal circuit element
according to the present invention;
FIG. 13 is an exploded perspective view illustrating main parts of a conventional
nonreciprocal circuit element;
FIG. 14 is a plan view illustrating the main parts of a conventional nonreciprocal
circuit element; and
FIG. 15 is a developed view of central conductors incorporated in the conventional
nonreciprocal circuit element.
DESCRIPTION OF THE PREFERRED EMBODIMENT
A nonreciprocal circuit element according to the present invention will be described
with reference to the accompanying drawings, in which FIG. 1 is a plan view of
a nonreciprocal circuit element according to the first embodiment of the present
invention, FIG. 2 is a front view of the nonreciprocal circuit element according
to the first embodiment, and FIG. 3 is a side view of the nonreciprocal circuit
element according to the first embodiment.
Further, FIG. 4 is a plan view of the nonreciprocal circuit element according
to the first embodiment in a state in which a first upper yoke is removed, FIG.
5 is a plan view of the nonreciprocal circuit element according to the first embodiment
in a state in which a first yoke and a magnet are removed, FIG. 6 is a cross-sectional
view taken along the line
6—
6 of FIG. 4, and FIG. 7 is a cross-sectional
view taken along the line
7—
7 of FIG. 4.
Furthermore, FIG. 8 is an exploded perspective view illustrating main
parts of the nonreciprocal circuit element according to the first embodiment, FIG.
9 is a developed view of central conductors incorporated in the nonreciprocal circuit
element according to the first embodiment, FIG. 10 is a plan view of a nonreciprocal
circuit element according to a second embodiment in a state in which an upper plate
of a first yoke is removed; FIG. 11 is a plan view of a nonreciprocal circuit element
according to a third embodiment in a state in which an upper plate of a first yoke
is removed, and FIG. 12 is an equivalent circuit diagram of the nonreciprocal circuit
element according to the present invention.
The configuration of a nonreciprocal circuit element according to a first embodiment
of the present invention, in which the nonreciprocal circuit element is employed
to an isolator, will now be described with reference to FIGS. 1 to
9. The
nonreciprocal circuit element includes a first yoke
1 formed of a box-shaped
magnetic plate (an iron plate or the like). The first yoke
1 has a rectangular
upper plate
1a, side plates
1b bent downward from four
sides of the upper plate
1a, and notch parts
1c formed
at a central portion between a pair of side plates
1b facing each
other along a vertical direction.
A rectangular (square) magnet
2 has two long sides
2a facing
each other, short sides
2b extending at right angle relative to the
long sides
2a, and quadrangular chamfers
2c provided
at four corners. The magnet
2 is mounted on the first yoke
1 by appropriate
means, such as an adhesive or the like, in a state in which ends of the short sides
2b placed at both sides are placed in the notch parts
1c
and the top surface of the magnet
2 contacts the inner surface of the
upper plate
1a.
A second yoke
3 formed of a magnetic box-shaped plate (an iron plate or
the like) has a rectangular bottom plate
3a, and four side plates
3b bent downward from four sides of the bottom plate
3a.
In a state in which the bottom plate
3a faces the upper plate
1a,
the second yoke
3 forms a closed magnetic circuit by connecting the side
plates
3b of the second yoke
3 to the side plates
1b
of the first yoke
1.
In the illustrative embodiment, an example in which the first and second yokes
1 and
3 have a box-shaped configuration has been described. However,
shapes of the first and second yokes
1 and
3 are not limited to this
configuration. For example, one of the first and second yokes
1 and
3
may be formed in a box-shaped, and the other may be formed in a U-shaped, so that
it is possible to form a closed magnetic circuit by connecting the both side plates
1b and
3b. Further, both the first and second yokes
1 and
3 may be formed in the U-shaped, so that it is possible to
form a closed magnetic circuit by connecting the both side plates
1b
and
3b.
A rectangular (square) and flat ferrite member
4, which is formed of YIG
(yttrium iron garnet), has two long sides
4a facing each other, two
short sides
4b facing each other, and chambers
4c formed
at four corners of the ferrite member
4.
As shown in FIG. 9, first, second and third central conductors
5,
6
and
7 formed of thin conductive plates such as copper or the like are formed
by notching metal plates, and extend outward from a centrally disposed, square
ground portion
8.
Each of the first, second and third central conductors
5,
6 and
7 has a slit formed lengthwise to be divided into two parts. Also, the first,
second and third central conductors
5,
6 and
7 have pairs
of conductor parts
5a,
6a, and
7a parallel
to one another, and first, second and third port portions
5b,
6b
and
7b provided at ends of the conductor parts
5a,
6a and
7a, respectively.
The first, second and third central conductors
5,
6 and
7
are configured such that a ground portion
8 is disposed under the ferrite
member
4. In such a state, the conductor parts
5a,
6a
and
7a are bent along the side and top surfaces of the ferrite
member
4.
In this case, the first, second and third central conductors
5,
6
and
7 are disposed on surfaces different in a vertical direction to be spaced
apart from one another by an angle of 120 degrees with a dielectric element (not
shown) interposed therebetween, and parts of the first, second and third central
conductors
5,
6 and
7 are disposed so as to intersect one
another in the vertical direction. In this case, as shown in FIG. 5, the first
and second port portions
5b and
6b are disposed on
one of the long sides
4a of the ferrite member
4, and the
third port portion
7b is disposed on the other long side
4a
of the ferrite member
4.
When the first, second and third central conductors
5,
6 and
7
are mounted on the ferrite member
4, as shown in FIG. 5, the conductor parts
5a and
6a of the first and second central conductors
5 and
6 are placed at the short sides
4b to be arranged
so as to traverse the longer face of the ferrite member
4 while the conductor
part
7a of the third central conductor
7 is placed at the
long side
4a so as to traverse the shorter face of the ferrite member
4.
At this time, the conductor parts
5a and
6a of the
first and second central conductors
5 and
6 extend the chamfers
4c
slanting with respect to the ferrite member
4.
A resin case
9, made of a synthetic resin mold, has a bottom wall
9a,
four side walls
9b extending upward from the bottom wall
9a,
a first receiving portion
9c having a rectangular (square) hole formed
in the central portion of the bottom wall
9a, and second receiving
portions
9d having holes formed in the bottom wall
9a along
the length direction of both sides of the first receiving portion
9c.
The resin case
9 is integrally formed with the second yoke
3 by
molding. Alternatively, the resin case
9 may be combined with the second
yoke
3 such that it is separately formed within the second yoke
3.
When the ferrite member
4 having the first, second and third central
conductors
5,
6 and
7 mounted thereon is arranged within the
first receiving portion
9c, a ground portion
8 corresponding
to one end of each of the first, second and third central conductors
5,
6 and
7 is connected to the bottom wall
3a of the second
yoke
3 disposed at the lower portion of the resin case
9, and the
second receiving portions
9d are arranged along the long sides
4a
of the ferrite member
4.
When the ferrite member
4 is arranged within the first receiving portion
9c, the respective short sides
4b of the ferrite member
4 are in proximity to the side plates
3b of the second yoke
3 with the sidewalls
9b interposed therebetween, so that the
ferrite member
4 are elongated between the pair of side plates
3b.
First, second and third chip capacitors C
1, C
2 and C
3
and a chip-type resistor R are accommodated in the second receiving portions
9,
and lower electrodes (not shown) of the first, second and third capacitors C
1,
C
2 and C
3 and an electrode
10a at one side of the resistor
R are connected to the bottom plate
3a of the second yoke
3.
Then, the respective port portions
5b and
6b of
the first and second central conductors
5 and
6 are connected to
upper electrodes (not shown) of the first and second capacitors C
1 and C
2
by soldering, while the third port portion
7b of the third central
conductor
7 is soldered to an upper electrode (not shown) of the third capacitor
C
3 and to the top surface of the other-end electrode
10b of
the resistor R.
In a state in which the magnet
2, the ferrite member
4 and the
resin
case
9 are interposed in the first and second yokes
1 and
3,
the first and second yokes
1 and
3 are combined with each other to
form a closed magnetic circuit composed of the first and second yokes
51
and
58, thereby completing the nonreciprocal circuit element.
When the first and second yokes
1 and
3 are combined with each
other, the lower surface of the magnet
2 does not contact with the side
plates
1b and
3b while the top surface of the ferrite
member
4 is disposed within the dimension of the bottom surface of the magnet
2 in a state in which the long sides of the magnet
2 are joined to
the long sides
4a of the ferrite member
4 and the short sides
2b of the magnet
2 are joined to the short sides
4b
of the ferrite member
4, respectively.
Consequently, each of the short sides
4b of the ferrite
member
4 becomes in proximity of extension lines of the side plate
1b
of the first yoke
1, so that the ferrite member
4 is elongated
between the pair of side plates
1b.
FIG. 10 shows a nonreciprocal circuit element according to a second embodiment,
in which the magnet
2 is rectangular, the chamfers
2c are
quadrangular, and four ends of the magnet
2 are placed within notch parts
1c of the first yoke
1.
The other configuration of the nonreciprocal circuit element is the same as that
of the nonreciprocal circuit element shown in the first embodiment. Therefore,
the same parts are designated by the same reference numerals, and an explanation
thereof will not be given.
FIG. 11 shows a nonreciprocal circuit element according to a second embodiment,
in which the magnet
2 is circular, and four ends of the magnet
2,
disposed crosswise, are placed within notch parts
1c of the first
yoke
1.
The other configuration of the nonreciprocal circuit element is the same as that
of the nonreciprocal circuit element shown in the first embodiment. Therefore,
the same parts are designated by the same reference numerals, and an explanation
thereof will not be given.
FIG. 12 is an equivalent circuit diagram of the nonreciprocal circuit element
according to the present invention used as an isolator. The first and second grounded
capacitors C
1 and C
2 are connected to one ends of the first and second
central conductors
5 and
6. The first and second port portions
5c
and
6c are formed as input and output ports. The third port portion
7d to which the third grounded capacitor C
3 and the resistor
R are connected is disposed at one end of the third central conductor
7.
Also, the other end of each of the first, second and third central conductors
5,
6 and
7 is grounded by the ground portion
8.
In the illustrative embodiment, the example in which the present invention is
applied to the isolator has been described. However, that present invention can
also be applied to a circulator configured such that the resistor R is not connected
to the central conductor.
As described above, the nonreciprocal circuit element according to the present
invention comprises a flat ferrite member, first, second and third central conductors
disposed on the ferrite member such that they are disposed on surfaces different
in a vertical direction with a dielectric element interposed therebetween, and
parts thereof intersecting one another in the vertical direction, a magnet disposed
on the central conductors, a first yoke disposed so as to cover the top surface
of the magnet, and a second yoke forming a closed magnetic circuit in combination
with the first yoke, the second yoke being disposed below the ferrite member. The
first yoke has a rectangular upper plate, a pair of side plates bent downward from
at least sides of the upper plate facing each other, and notch parts formed in
the central portion of the pair of side plates. The respective ends of the magnet
are placed within the notch parts.
According to the above construction, the magnet can be enlarged and the
ferrite member provided corresponding to the magnet can also be enlarged, which
increases the lengths of conductor parts of the central conductors mounted on the
ferrite member, thereby achieving high performance of the nonreciprocal circuit
device without adversely affecting miniaturization.
Since the ends of the ferrite member are disposed in proximity to extension
lines of a pair of side plates, the ferrite member can be maximally elongated between
the pair of side plates. Accordingly, the lengths of conductor parts of the central
conductors mounted on the ferrite member can be increased, thereby acquiring excellent
nonreciprocal circuit device.
Also, since the magnet has a quadrangular shape having long sides and short
sides and short-side ends of the magnet are placed within the notch parts, the
effective area of the magnet can be enlarged, thereby achieving high performance.
Further, since chamfers are formed at corners of the magnet, positioning
of the magnet relative to the first yoke is easily made, thereby achieving excellent productivity.
The ferrite member has a quadrangular shape having long sides and short sides.
In a state in which the long sides of the magnet are joined to the long sides of
the ferrite member and the short sides of the magnet are joined to the short sides
of the ferrite member, respectively, the top surface of the ferrite member is disposed
within the dimension of the bottom surface of the magnet, and the short sides of
the ferrite member are disposed in proximity to the extension lines of the side
plates. Thus, the lengths of the central conductors mounted on the ferrite member
can be increased, thereby acquiring an excellent nonreciprocal circuit device.
Also, since the chamfers are formed at corners of the ferrite member, conductor
parts of the central conductors can be locked thereto to be fastened, thereby securing
mounting of the central conductors. Also, since the length of conductor parts of
the central conductors mounted on the ferrite member are increased, high performance
of the nonreciprocal circuit device can be achieved.
Since the bottom surface of the magnet placed within the notch parts does not
contact with the side plates and the second yoke, it is possible to obtain a desirable
magnetic bias in the closed magnetic circuit formed between the first and second yokes.
The nonreciprocal circuit element of the present invention comprises a resin
case disposed within the second yoke, the resin case having a first receiving portion
in which the ferrite member is accommodated, and a plurality of second receiving
portions in which a plurality of capacitors connected to the central conductors
are accommodated, thereby achieving good assembling performance.
Further, since the first receiving portion is arranged at the central portion
of the resin case and the second receiving portions are arranged at both sides
of the first receiving portion along the long sides of the magnet and the ferrite
member, the lengths of the ferrite member can be maximally increased, which increases
the lengths of the central conductors mounted on the ferrite member. Thus, highly
efficient, miniaturized devices can be acquired.
*
