JP2005136650A - Non-reciprocal circuit element - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a compact non-reciprocal circuit element whose insertion loss can be reduced. <P>SOLUTION: This non-reciprocal circuit element is provided with a plurality of center electrodes arranged so that they cross electrically, a magnetic body for microwave, a permanent magnet and a capacity for matching. The center electrodes are laminated on a face where the microwave magnetic body of the permanent magnet is arranged, one end of the center electrode is connected to an electrode for connection formed on the micro-wave magnetic body surface, and the other end of the center electrode is connected to the capacity for matching or the input/output terminal. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to non-reciprocal circuit elements such as isolators and circulators used in high-frequency wireless communication devices such as mobile phones.

  Miniaturization is strongly demanded in the portable radio communication equipment market represented by mobile phones, and miniaturization is inevitably required for parts used in radio communication equipment. Non-reciprocal circuit elements used in high-frequency circuits such as wireless communication devices are no exception.

  FIG. 4 shows a structure of a non-reciprocal circuit element currently used, and FIG. 5 shows an exploded view thereof. As shown in the drawing, a plurality of center electrodes are arranged under the permanent magnet so as to cross each other. However, in order to maintain insulation, a highly insulating sheet such as polyimide is disposed between the center electrodes. A microwave magnetic material is disposed under these central electrodes, and further, although not shown here, the whole is covered with a yoke that also serves as a case in order to form a closed magnetic circuit.

  Alternatively, Patent Document 1 proposes a structure in which insulation between a plurality of center electrodes is maintained with a microwave magnetic material or a dielectric material, and the conventionally separated center electrode and microwave magnetic material are integrated. In such a structure, the center electrode can be arranged without depending on the mechanical work, which is advantageous for downsizing.

  Alternatively, Patent Document 2 proposes an integrated structure using a microwave magnetic material as an insulating film for a matching capacitor.

  Alternatively, Patent Document 3 proposes that the center electrode is integrated by an insulating film to simplify the assembly process.

Japanese Patent Laid-Open No. 06-291514 Japanese Patent Laid-Open No. 06-291515 Japanese Patent Laid-Open No. 08-008612

  First, in the structure of the conventional non-reciprocal circuit device as shown in FIG. 4, the center electrode must be accurately arranged manually or by a machine, and there is a limit to miniaturization in terms of accuracy and cost.

  Further, in the structure in which the center electrodes are insulated by the microwave magnetic material proposed in Patent Document 1 and a plurality of center electrodes are stacked, the connection to the matching capacitor is performed from the lower part of the microwave magnetic body stack. Is inferred from the drawings. That is, with this structure, it is necessary to arrange a matching capacitor or a structure for connection under the microwave magnetic laminate, which is disadvantageous in terms of reducing the height of the nonreciprocal circuit element.

  In the case where the microwave magnetic material described in Patent Document 2 is used as an insulating film for a matching capacitor, a current flowing through the matching capacitor generates a magnetic field, which is caused by a complex component of permeability of the microwave magnetic material. Cause unnecessary power consumption. That is, there is a problem that the insertion loss increases and the characteristics as a non-reciprocal circuit element deteriorate.

  In the method of creating and connecting a central electrode body with an insulating film sandwiched between a plurality of center electrodes described in Patent Document 3, the center electrode placed at the bottom and the uppermost part are disposed. There is a difference in height from the center electrode. For this reason, a structure for compensating for the difference in height is required to eliminate the connection failure and to construct the nonreciprocal circuit element with high reliability, which increases the number of processes and is advantageous in terms of cost. Absent.

  An object of the present invention is to propose a non-reciprocal circuit element structure that avoids the above-described problems and is small, low-profile, and inexpensive.

  The non-reciprocal circuit device of the present invention is a non-reciprocal circuit device comprising a plurality of center electrodes arranged so as to cross each other in an electrically insulated state, a microwave magnetic material, a permanent magnet, and a matching capacitor. The center electrode is formed by laminating the surface of the permanent magnet on which the microwave magnetic body is disposed, and one end of the center electrode is connected to a connection electrode formed on the surface of the microwave magnetic body, The other end of the center electrode is connected to the matching capacitor or the input / output terminal.

  In the nonreciprocal circuit device of the present invention, the matching capacitor may be formed by being laminated together with the central conductor connection electrode on the surface of the permanent magnet where the microwave magnetic body is disposed.

  According to the present invention, it is possible to realize a non-reciprocal circuit device that is small in size, has a small number of processes, and is advantageous for cost reduction.

Embodiments of the present invention will be described below with reference to the accompanying drawings.
FIG. 1 is a diagram showing a first embodiment of the present invention. The assembly 1 is formed by integrating a permanent magnet and a central electrode portion, 10 is a microwave magnetic body, and 13 is a laminated body incorporating a matching capacitor. FIG. 2 is an exploded perspective view of the assembly 1. Reference numeral 4 denotes a permanent magnet for applying a static magnetic field to the microwave magnetic body, and a ferrite magnet is usually used. Reference numerals 3a, 3b, and 3c denote center electrodes, which intersect each other while being insulated from each other by the dielectrics 5a and 5b. One end of each of the center electrodes 3a, 3b, 3c is connected to the matching capacitor electrode 12 provided on the top surface of the multilayer body 13 through the through hole 9 formed on the dielectric and the connection electrode 6 or directly. The The other ends of the center electrodes 3a, 3b, 3c are connected to the connection electrode 7 provided on the surface of the microwave magnetic body 10 through the through hole 8 and the connection electrode 6 or directly. Reference numeral 11 denotes a resistor required when the nonreciprocal circuit device of the present invention is used as an isolator. A concave portion can be provided in a portion of the dielectric 5b in contact with the resistor 11 so that the bonding between the electrodes of the assembly 1 and the laminate 13 is not hindered.

  Next, a method for manufacturing the assembly 1 in which the permanent magnet and the central electrode portion are integrated will be described. First, the center electrode 3b is formed on the main surface of the permanent magnet by selectively applying a conductor by screen printing. Next, in order to improve the flatness, a dielectric is applied by screen printing to a portion other than the center electrode 3b. Next, a dielectric sheet 5a on which a through hole is provided and the center electrode 3a is printed is formed. Next, a dielectric sheet 5b provided with a through hole, a center electrode 3c, and a connection electrode 6 is formed. Finally, the dielectric sheets 5a and 5b are stacked on the main surface of the permanent magnet, and are pressed and fired.

In the non-reciprocal circuit device configured as described above, it is not necessary to mechanically assemble the center electrode, and it is necessary to arrange a connection structure on the microwave magnetic body for connection between the center electrode and the matching capacitor. Will also disappear. In addition, the height difference between the center electrodes can be easily filled with the through holes.
Furthermore, with regard to the matching capacitance, it is possible to prevent deterioration of insertion loss by creating the laminated dielectric 13 using a material having a permeability of approximately 1 in the operating frequency band and a very small complex component causing loss. I can do it.

  FIG. 3 is an exploded perspective view showing the assembly of the second embodiment of the present invention. Reference numeral 14 denotes a matching capacitance electrode, which is connected to an external circuit directly or through the through hole 9 and the connection electrode 6. Reference numeral 15 denotes a ground side electrode of a matching capacitor. It is connected to the ground connection electrode arranged on the microwave magnetic body directly or through the through hole 8 and the installation electrode 6.

  By adopting such a structure, it is not necessary to separately incorporate a matching capacitor, the number of processes can be reduced, and an inexpensive nonreciprocal circuit device can be realized.

  The nonreciprocal circuit device of the present invention can be used in high-frequency wireless communication devices such as mobile phones and mobile terminals.

FIG. 2 is a diagram showing a first example of a non-reciprocal circuit device according to the present invention. 1 is an exploded perspective view of a permanent magnet and a center electrode portion of a first embodiment of a nonreciprocal circuit device according to the present invention. It is the disassembled perspective view which showed the 2nd Example of the nonreciprocal circuit device by this invention. It is a perspective view of the center electrode and microwave magnetic body part of the conventional nonreciprocal circuit device. It is a disassembled perspective view of the center electrode of the conventional nonreciprocal circuit device.

Explanation of symbols

1: Aggregate
2a, 2b: Insulation sheet
3a, 3b, 3c: Center electrode
4: Permanent magnet
5a, 5b: Dielectric layer
6: Connecting electrode
7: Connecting electrode
8: Through hole for grounding
9: Through hole
10: Microwave magnet
11: Resistance
12: Capacitance electrode for matching
13: Multilayer dielectric
14: Capacitance electrode for matching
15: Matching capacitance ground electrode

Claims (2)

In a non-reciprocal circuit element comprising a plurality of center electrodes arranged so as to cross each other in an electrically insulated state, a microwave magnetic material, a permanent magnet, and a matching capacitor, the center electrode is connected to the permanent magnet. It is formed by laminating on the surface on which the microwave magnetic body is disposed, one end of the center electrode is connected to a connection electrode formed on the surface of the microwave magnetic body, and the other end of the center electrode is A non-reciprocal circuit device connected to a matching capacitor or an input / output terminal. 2. The nonreciprocal circuit device according to claim 1, wherein the matching capacitor is formed by being laminated together with the central conductor connection electrode on a surface of the permanent magnet on which the microwave magnetic body is disposed. A nonreciprocal circuit device.

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