JP2005079813A - Non-reciprocal circuit element and communication device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain a non-reciprocal circuit element and a communication device in which the capacity value of a matching capacitative element included in a multi-layered substrate can be made large and the trimming range of the capacity value can be extended. <P>SOLUTION: The non-reciprocal circuit element is composed of: a permanent magnet; a center electrode assembly constituted by arranging a plurality of center electrodes on a ferrite plate; a multi-layered substrate 30 in which the center electrode assembly is arranged on a first main surface and the matching capacitative element and a terminal resistive element are incorporated; and a metallic case. Hot side capacitor electrodes 35A, 35B and 35C of the matching capacitative element are arranged on the inside of the first layer of a 2nd main surface (dielectric sheet 46) located on the opposite side to the first main surface, and the trimming of a capacity is conducted from the second main surface side. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a nonreciprocal circuit element, in particular, a nonreciprocal circuit element used as a circulator or an isolator, and a communication apparatus including the nonreciprocal circuit element.

  Conventionally, non-reciprocal circuit elements such as circulators and isolators have a characteristic of transmitting signals only in a predetermined direction and not transmitting in the reverse direction, and are used in mobile communication devices such as automobile phones and mobile phones. Used in the transmission circuit section.

  A non-reciprocal circuit element of this type is known as disclosed in Patent Document 1, and includes a center electrode assembly in which a plurality of center electrodes are arranged on a ferrite to which a DC magnetic field is applied from a permanent magnet, and a first main surface. The central electrode assembly is disposed, and a multilayer substrate including a matching capacitor element and a termination resistor element, which are electrically connected to the center electrode, is a main component.

  In the matching capacitor element, a hot side electrode is disposed on the first main surface side in the multilayer substrate, and the capacity of the hot side electrode is trimmed by laser irradiation or the like. However, since the center electrode connection electrode is arranged on the first main surface of the multilayer substrate, the arrangement of the hot side electrode is restricted and a large capacitance value cannot be obtained, the trimming region is restricted, and the capacitance adjustment width is limited. It had the problem of being small.

Such a problem is caused by the size relationship between the multilayer substrate and the ferrite. That is, the size of the permanent magnet needs to be larger than that of ferrite because it is necessary to apply a magnetic field uniformly to the ferrite. The size of the multilayer substrate needs to be wide in order to make the matching capacitance value as large as possible. However, the size is limited to the size of the permanent magnet due to the external constraints of the product. As a result, the size of the ferrite is slightly smaller than the size of the multilayer substrate. Therefore, it is difficult to dispose the center electrode connection electrode disposed on the first main surface of the multilayer substrate for connection with the center electrode disposed on the ferrite at the end of the first main surface. This is placed on the center side of the first main surface, which places great restrictions on the placement of the hot-side electrode and the trimming region of the matching capacitor.
JP 2003-142903 A

  SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a nonreciprocal circuit device and a communication device that can increase the capacitance value of a matching capacitor element built in a multilayer substrate and have a large trimming range of the capacitance value. .

In order to achieve the above object, a non-reciprocal circuit device according to the present invention comprises:
(A) a permanent magnet;
(B) a center electrode assembly in which a plurality of center electrodes are arranged in a ferrite to which a DC magnetic field is applied by the permanent magnet;
(C) a matching capacitor having a first main surface on which the center electrode assembly is disposed and a second main surface located on the opposite side of the first main surface and electrically connected to the center electrode A multi-layer substrate having a built-in element and a terminal resistance element;
(D) a metal case surrounding the permanent magnet, the central electrode assembly, and the multilayer substrate;
(E) the hot-side electrode of the matching capacitive element is disposed in the second main surface or in the vicinity of the second main surface;
It is characterized by.

  In the nonreciprocal circuit device according to the present invention, since the hot side electrode of the matching capacitor is arranged on the second main surface of the multilayer substrate or in the vicinity of the second main surface, the hot side electrode is restricted as in the conventional case. As compared with the arrangement on the first main surface side having a large size, the matching capacitance value can be set large with the hot side electrode as a large area, and the hot side electrode is trimmed from the second main surface side. Therefore, the trimming area becomes large and the adjustment range of the capacitance value becomes large. As a result, the yield rate is improved. That is, a plurality of external connection terminal electrodes are arranged on the second main surface of the multilayer substrate, but these terminal electrodes are arranged at the end of the second main surface, so that the arrangement of the hot side electrodes and the trimming region are arranged. It does not give a big restriction.

  Furthermore, in the nonreciprocal circuit device according to the present invention, stray capacitance is generated between the hot-side electrode of the matching capacitance and the metal case, and the matching capacitance is increased. In other words, if the same matching capacitance is obtained, the multilayer substrate can be made thin, leading to a reduction in the height of the nonreciprocal circuit element.

  In the nonreciprocal circuit device according to the present invention, the hot-side electrode of the matching capacitor may be disposed on the second main surface of the multilayer substrate. In this case, in order to avoid a problem that the hot-side electrode contacts the ground electrode of the metal case, a plurality of external connection terminal electrodes are provided on the second main surface so as to protrude, or the second main surface is recessed. And a hot-side electrode may be disposed in the recess.

  In addition, the communication device according to the present invention includes the non-reciprocal circuit element, and can provide a highly reliable communication device including the non-reciprocal circuit element whose matching capacitance is well adjusted. .

  Embodiments of a nonreciprocal circuit device and a communication device according to the present invention will be described below with reference to the accompanying drawings. In the attached drawings, the hatched portion other than the cross-sectional view is a conductor.

(See Example 1, FIGS. 1 to 8)
FIG. 1 shows an exploded perspective view of Example 1 of the nonreciprocal circuit device according to the present invention, and FIG. 3 shows an equivalent circuit thereof. This non-reciprocal circuit element 1A is a three-terminal type lumped constant type isolator. As shown in FIG. 1, a metal case composed of an upper metal case 4 and a lower metal case 8, a permanent magnet 9, A center electrode assembly 13 including a ferrite 20 and center electrodes 21, 22, and 23, and a multilayer substrate 30 including a resistance element R and matching capacitance elements C 1, C 2, and C 3 (see FIGS. 2 and 3) are provided. .

  The permanent magnet 9, the center electrode assembly 13 and the multilayer substrate 30 are accommodated in a box formed by the metal cases 4 and 8. The lower metal case 8 is molded with resin, and the hatched portion in FIG. 1 is exposed as a conductor portion. In order to form a magnetic circuit, the metal cases 4 and 8 are made of, for example, a material made of a ferromagnetic material such as soft iron or ferrite, and the surface thereof is plated with Ag or Cu.

  In the center electrode assembly 13, three center electrodes 21, 22, and 23 are arranged on the upper surface of the rectangular microwave ferrite 20 so as to intersect with each other at approximately 120 degrees with an insulating layer (not shown) interposed therebetween. ing. In the first embodiment, the center electrodes 21, 22, and 23 are each composed of two lines. Both end portions of the center electrodes 21, 22, and 23 wrap around the lower surface of the ferrite 20, and are electrically connected to electrodes 31A, 31B, 31C, 31D, 31E, and 31F formed on the multilayer substrate 30 described below with reference to FIG. Connected to.

  As shown in FIG. 2, the multilayer substrate 30 is obtained by stacking six ceramic dielectric sheets 41 to 46. Conductive layers are formed on the upper surfaces of the sheets 41 to 46, respectively.

  The first dielectric sheet 41 (first main surface) is provided with center electrode connecting electrodes 31A to 31F, and the electrodes 31A to 31F are provided with via holes 38a to 38f, respectively. The second-layer dielectric sheet 42 is provided with a cold-side capacitor electrode 32, and via holes 38g to 38i are provided at predetermined positions.

  The third-layer dielectric sheet 43 is provided with hot-side capacitor electrodes 33A, 33B, and 33C, and the electrode 33C is provided with a via hole 38j. The fourth-layer dielectric sheet 44 is provided with a cold-side capacitor electrode 34 and a via hole 38k.

  The fifth-layer dielectric sheet 45 is provided with hot-side capacitor electrodes 35A, 35B, and 35C, and a resistance film 51 is provided. The sixth-layer dielectric sheet 46 (second main surface) is provided with input / output connection terminal electrodes 36A and 36B and a ground connection terminal electrode 36C at both ends thereof.

  The dielectric sheets 41 to 46 having the various electrodes are sequentially stacked and fired, and a predetermined electrical connection is made through the via holes 38a to 38k, thereby forming the multilayer substrate 30 constituting the equivalent circuit shown in FIG. Here, the matching capacitors C1, C2, and C3 are formed by the third-layer hot-side capacitor electrodes 33A, 33B, and 33C and the cold-side capacitor electrodes 32 and 34 disposed above and below the third-layer hot-side capacitor electrodes 33A, 33B, and 33C. The cold-side capacitor electrode 34 and the fifth-layer hot-side capacitor electrodes 35A, 35B, and 35C are formed. Further, the resistance film 51 functions as a termination resistor R.

  The capacitance values of the matching capacitors C1, C2, and C3 are measured with the multilayer substrate 30 alone, and then irradiated with a laser from the sixth-layer dielectric sheet 46 to provide hot-side capacitor electrodes 35A, 35B, and 35C. Is adjusted by trimming. Also, laser trimming is performed on the resistance film 51 after measuring its resistance value. In FIG. 2E, the trimming marks on the electrodes 35A, 35B, 35C and the resistance film 51 are indicated by reference numeral 81, and in FIG. 2F, the trimming marks remaining on the dielectric sheet 46 are indicated by reference numeral 82. FIG. 4 is a cross-sectional view showing the trimming state for the electrodes 35A, 35B, and 35C, and the thickness T of the sixth-layer dielectric sheet 46 is 50 μm that allows laser trimming.

  In the non-reciprocal circuit device 1A according to the first embodiment, the hot-side capacitor electrodes 35A, 35B, and 35C of the matching capacitors C1, C2, and C3 are arranged on the inner side of the second main surface of the multilayer substrate 30. Therefore, the second main surface is wide only by forming the terminal electrodes 36A, 36B, and 36C at both ends thereof, and the capacitor electrodes 35A, 35B, and 35C can be widened to obtain a matching capacitance value. Can be set large. For the same reason, as shown in FIG. 5A, the trimming region 80 is large and the adjustment range of the capacitance value is large.

  Incidentally, for comparison, FIG. 5B shows a state in which the hot-side capacitor electrodes 35A, 35B, and 35C are arranged inside one layer of the first main surface of the multilayer substrate 30 for comparison. In this case, since the center electrode connection electrodes 31A to 31F are provided on the first main surface, the areas of the hot-side capacitor electrodes 35A, 35B, and 35C are narrow, and the trimming region is also narrowed.

  Further, as shown in FIG. 6B, since the stray capacitance C is generated between the hot side capacitor electrodes 35A, 35B, and 35C and the lower metal case 8, the matching capacitance is increased. In other words, if the same matching capacitance is obtained, the number of sheets constituting the multilayer substrate 30 can be reduced as shown in FIG. 6C, the multilayer substrate 30 becomes thinner, and the nonreciprocal circuit element 1A is reduced in height. Leads to.

  For comparison, FIG. 6A shows a state in which hot-side capacitor electrodes 35A, 35B, and 35C are arranged in the second layer as in the prior art. In this case, since the cold-side capacitor electrode 32 is disposed in the fifth layer, the stray capacitance C does not occur between the lower metal case 8 and the fifth layer.

  By the way, the hot-side capacitor electrodes 35A, 35B, and 35C may be disposed on the second main surface of the multilayer substrate 30. In this case, in order to prevent the electrodes 35A, 35B, and 35C from coming into contact with the ground electrode of the lower metal case 8, as shown in FIG. 7, external connection terminal electrodes 36A, 36B provided on the second main surface thereof. , 36C may be provided in a protruding state. Alternatively, as shown in FIG. 8, a recess 61 may be provided on the second main surface of the multilayer substrate 30. The recess 61 is formed largely in a region other than the portion where the external connection terminal electrodes 36A, 36B, and 36C are disposed. Further, the electrodes 35A, 35B, and 35C arranged on the second main surface may be covered with an insulating material.

(See Example 2, FIGS. 9 to 13)
FIG. 9 shows an exploded perspective view of Example 2 of the nonreciprocal circuit device according to the present invention, and FIG. 11 shows an equivalent circuit thereof. This nonreciprocal circuit device 1B is a two-terminal type lumped constant type isolator, and members and portions common to those of the first embodiment are denoted by the same reference numerals as in FIGS. 1 to 8, and redundant description is omitted.

  Since the second embodiment is a two-terminal type, the center electrode assembly 13 is arranged so that the center electrodes 21 and 22 intersect each other at approximately 90 °. The center electrode 21 is composed of two lines, and the center electrode 22 is composed of three lines.

  As shown in FIG. 10, the multilayer substrate 30 is a laminate of six ceramic dielectric sheets 41 to 46, and a conductor layer is formed on the upper surface of each of the sheets 41 to 46.

  The first dielectric sheet 41 (first main surface) is provided with center electrode connecting electrodes 31A to 31D, and the electrodes 31A to 31D are provided with via holes 38a to 38d, respectively. The second dielectric sheet 42 is provided with a capacitor electrode 32 having a matching capacitance C2, and via holes 38e to 38h are provided at predetermined positions.

  The third-layer dielectric sheet 43 is provided with capacitor electrodes 33 having matching capacitances C1 and C2, and via holes 38i to 38l are provided at predetermined positions. The fourth dielectric sheet 44 is provided with a capacitor electrode 34A having a matching capacitance C1 and a capacitor electrode 34B having a matching capacitance C2, and via holes 38m to 38o are provided at predetermined positions.

  The fifth dielectric sheet 45 is provided with capacitor electrodes 35 having matching capacitances C1 and C2, and a resistance film 51 and connecting electrodes 52A and 52B. The sixth-layer dielectric sheet 46 (second main surface) is provided with input / output connection terminal electrodes 36A and 36B and a ground connection terminal electrode 36C at both ends thereof.

  In the second embodiment which is a two-terminal type isolator, the capacitor electrodes 33 and 35 function as hot-side capacitor electrodes of the matching capacitor C2. The capacitor electrodes 32 and 34B function as cold side capacitor electrodes of the matching capacitor C2.

  The dielectric sheets 41 to 46 having the various electrodes are sequentially stacked and fired, and a predetermined electrical connection is made through the via holes 38a to 38o, thereby forming the multilayer substrate 30 constituting the equivalent circuit shown in FIG.

  The capacitance values of the matching capacitors C1 and C2 are trimmed with respect to the hot-side capacitor electrode 35 by irradiating a laser from the sixth-layer dielectric sheet 46 after measuring the capacitance value with the multilayer substrate 30 alone. To adjust. Also, laser trimming is performed on the resistance film 51 after measuring its resistance value. In FIG. 10E, a trimming mark on the electrode 35 and the resistance film 51 is denoted by reference numeral 81, and in FIG. 10F, a trimming mark remaining on the dielectric sheet 46 is denoted by reference numeral 82. The state of trimming for the electrode 35 is as shown in FIG.

  Even in the nonreciprocal circuit device 1B according to the second embodiment, since the hot-side capacitor electrode 35 is disposed on the inner side of the second main surface of the multilayer substrate 30, both end portions thereof are provided on the second main surface. Further, the terminal electrodes 36A, 36B, and 36C are only formed, and are widely vacant, so that the hot-side capacitor electrode 35 can be widened and the matching capacitance value can be set large. For the same reason, as shown in FIG. 12A, the trimming region 80 is large and the adjustment range of the capacitance value is large.

  Incidentally, for comparison, FIG. 12B shows a state in which the hot-side capacitor electrode 35 is arranged on one layer inside the first main surface of the multilayer substrate 30 for comparison. In this case, since the center electrode connection electrodes 31A to 31D are provided on the first main surface, the area of the hot-side capacitor electrode 35 is narrow and the trimming region is also narrowed.

  Further, as shown in FIG. 13B, since the stray capacitance C is generated between the hot-side capacitor electrode 35 and the lower metal case 8, the matching capacitance is increased. In other words, if the same matching capacitance is obtained, the number of sheets constituting the multilayer substrate 30 can be reduced as shown in FIG. 13C, the multilayer substrate 30 becomes thinner, and the nonreciprocal circuit element 1B is reduced in height. Leads to.

  For comparison, FIG. 13A shows a state where the hot-side capacitor electrode 35 is arranged in the second layer as in the prior art. In this case, since the cold-side capacitor electrode 32 is disposed in the fifth layer, the stray capacitance C does not occur between the lower metal case 8 and the fifth layer.

  Incidentally, the hot-side capacitor electrode 35 may be disposed on the second main surface of the multilayer substrate 30 as in the first embodiment described with reference to FIGS.

(See Example 3, FIG. 14)
FIG. 14 is an exploded perspective view of the non-reciprocal circuit device according to the third embodiment of the present invention. This non-reciprocal circuit device 1C is a two-terminal type lumped constant isolator similar to the second embodiment. This non-reciprocal circuit device 1C has a center electrode assembly 13 composed of a rectangular parallelepiped ferrite 20 and center electrodes 21 and 22 intersecting with each other, and two permanent magnets 9 and 9 arranged on a multilayer substrate 30, and a metal case 14. The equivalent circuit is the same as that of the second embodiment (see FIG. 11).

  Therefore, the configuration of the multilayer substrate 30 is the same as that of the second embodiment (see FIG. 10), and the operational effects such as capacitance trimming are the same as described in the second embodiment.

(See Example 4, FIG. 15)
A communication apparatus (mobile phone) according to the present invention will be described as a fourth embodiment with reference to FIG.

  FIG. 15 shows an electric circuit of the RF portion of the mobile phone 220, where 222 is an antenna element, 223 is a duplexer, 231 is a transmission side isolator, 232 is a transmission side amplifier, 233 is a band pass filter for transmission side stages, 234 is A transmission-side mixer, 235 is a reception-side amplifier, 236 is a reception-side interband bandpass filter, 237 is a reception-side mixer, 238 is a voltage-controlled oscillator (VCO), and 239 is a local bandpass filter.

  Here, the nonreciprocal circuit elements 1A, 1B, and 1C of the first, second, and third embodiments can be used as the transmission-side isolator 231. By mounting these nonreciprocal circuit elements, it is possible to realize a highly reliable mobile phone including a nonreciprocal circuit element whose matching capacitance is well adjusted.

(Other examples)
The nonreciprocal circuit device and the communication device according to the present invention are not limited to the above-described embodiments, and can be changed to various configurations within the scope of the gist.

  For example, the detailed structures of the upper metal case 4, the lower metal case 8, the center electrode assembly 13, the multilayer substrate 30, the ferrite 20, and the like are arbitrary. In particular, at least one of the plurality of hot-side electrodes having a matching capacitance may be arranged in the second main surface or in the vicinity of the second main surface.

  In addition to the isolators shown in the first, second, and third embodiments, a circulator can be configured. Furthermore, the present invention can be applied to various nonreciprocal circuit elements in addition to isolators and circulators.

  In the fourth embodiment, a mobile phone has been described as an example of the communication device. However, the present invention is not limited to this and can be applied to other communication devices.

It is a disassembled perspective view which shows Example 1 of the nonreciprocal circuit device based on this invention. It is a top view which shows the multilayer substrate in Example 1 for every layer. 2 is an electrical equivalent circuit diagram of Example 1. FIG. FIG. 3 is a cross-sectional view illustrating a trimming state according to the first exemplary embodiment. It is explanatory drawing which shows the trimming area | region of a matching capacity | capacitance, (A) shows Example 1, (B) shows a comparative example. It is explanatory drawing which shows the formation state of matching capacity | capacitance, (A) shows a comparative example, (B) shows Example 1, (C) shows the modification. 6 is a perspective view showing a modification of the multilayer substrate in Example 1. FIG. 6 is a perspective view showing another modification of the multilayer substrate in Example 1. FIG. It is a disassembled perspective view which shows Example 2 of the nonreciprocal circuit device based on this invention. It is a top view which shows the multilayer board | substrate in Example 2 for every layer. 6 is an electrical equivalent circuit diagram of Example 2. FIG. It is explanatory drawing which shows the trimming area | region of a matching capacity | capacitance, (A) shows Example 2, (B) shows a comparative example. It is explanatory drawing which shows the formation state of matching capacity | capacitance, (A) shows a comparative example, (B) shows Example 1, (C) shows the modification. It is a disassembled perspective view which shows Example 3 of the nonreciprocal circuit device based on this invention. It is a block diagram which shows the electric circuit of the communication apparatus (Example 4) which concerns on this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Non-reciprocal circuit element 4 ... Upper metal case 8 ... Lower metal case 9 ... Permanent magnet 13 ... Center electrode assembly 20 ... Ferrite 21, 22, 23 ... Center electrode 30 ... Multilayer substrate 35, 35A-35C ... Hot side Capacitor electrodes 36A to 36C ... External connection terminal electrodes 41 to 46 ... Dielectric sheet 51 ... Resistive film 61 ... Recess 80 ... Trimming area 81, 82 ... Trimming mark 120 ... Mobile phone (communication device)
C1, C2, C3 ... Matching capacitance R ... Termination resistance

Claims (5)

With permanent magnets,
A center electrode assembly in which a plurality of center electrodes are arranged in a ferrite to which a DC magnetic field is applied by the permanent magnet;
A matching capacitive element having a first main surface on which the center electrode assembly is arranged and a second main surface located on the opposite side of the first main surface, and electrically connected to the center electrode, and a termination A multilayer substrate with a built-in resistance element;
A metal case surrounding the permanent magnet, the central electrode assembly and the multilayer substrate;
The hot electrode of the matching capacitive element is disposed in the vicinity of the second main surface or the second main surface;
A nonreciprocal circuit device characterized by the above.   A hot-side electrode of the matching capacitive element is disposed on a second main surface of the multilayer substrate, and a plurality of external connection terminal electrodes are provided on the second main surface in a protruding state. The nonreciprocal circuit device according to claim 1.   2. The nonreciprocal circuit device according to claim 1, wherein a recess is provided in a second main surface of the multilayer substrate, and a hot-side electrode of the matching capacitor is disposed in the recess.   4. The nonreciprocal circuit device according to claim 1, wherein a capacitance of the hot side electrode is trimmed from the second main surface side. 5.   A communication apparatus comprising the nonreciprocal circuit device according to claim 1, 2, 3, or 4.

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