JP5168505B2 - High frequency composite parts - Google Patents

Description

  The present invention relates to a high-frequency composite component whose main purpose is to switch signals of a mobile phone or the like.

  Conventionally, as a high-frequency composite component of this type, Patent Document 1 discloses a triple-band compatible high-frequency composite component as shown in FIG. 10. It consists of chip parts.

  This high-frequency composite component includes a high-frequency switch. In the high-frequency switch, transmission / reception is switched by applying or not applying a DC voltage to the control terminal Vc1. Since no voltage is applied to the control terminal Vc1 during signal reception, the diodes DG1 and DG2 are in the OFF state, and the reception signal is transmitted from the antenna terminal ANT to the reception side terminal Rx.

  At the time of signal transmission, the diodes DG1 and DG2 are turned on by applying a voltage to the control terminal Vc1. Here, the inductance component of the diode DG2 and the capacitor CG6 connected to the ground constitute a series resonance so that the impedance of the transmission line LG2 is close to infinity when viewed from the transmission side at the transmission frequency of the transmission signal. If designed, the transmission signal is hardly transmitted to the receiving side.

  The diode DG2 and the capacitor CG6 are mounted on one main surface of the multilayer substrate, and the transmission line LG2 is formed in the multilayer substrate. The connection between the diode DG2 and the capacitor CG6 and the connection between the diode DG2 and the transmission line LG2 are mainly made by wiring electrodes formed on the surface and side surfaces of the multilayer substrate.

JP 2004-7756 A

  However, since the connection between the diode and the capacitor constituting the resonance circuit and the connection between the diode and the transmission line are made by the wiring electrode, an inductance component is generated in the wiring electrode, and this is connected in series with the inductance component possessed by the diode. To occur. In the LC series resonance circuit, since the impedance increases as the inductance component increases, there is a problem in that the isolation characteristic between the transmission side and the reception side is deteriorated and leakage of the transmission signal to the reception circuit side is increased.

  In order to solve the above problems, an object of the present invention is to reduce the inductance component generated by the connection between the diode and the capacitor and the connection between the diode and the transmission line.

The present invention provides a multilayer substrate in which dielectric layers and conductive films are alternately laminated, an electrode formed on one main surface of the multilayer substrate, a diode mounted on the electrode, and the conductive layer in the multilayer substrate. A high-frequency composite component comprising a high-frequency switch having a capacitor and a transmission line formed using a film and a ground electrode formed on the outer surface of the multilayer substrate, the capacitor having one end connected to the ground electrode The other end side is connected to the anode of the diode, the transmission line is connected to the cathode of the diode at one end side, the diode is mounted on a pair of electrodes, and the transmission line is directly below the electrode on one side. One end side is disposed, and an electrode on the other end side of the capacitor is disposed directly below the electrode on the other side, and the connection between the diode and the capacitor is connected. Connection of the fine the diode and the transmission line is directly connected only via holes, at least a portion of the conductive film forming the capacitor and the transmission line, in the stacking direction of the multilayer substrate, one main of the multilayer substrate The high-frequency composite component is disposed within a projected area of the diode mounted on a surface .

  In the present invention, the electrode on which the diode is mounted may be a tip of the via hole connected to one main surface of the multilayer substrate.

  According to the present invention, by directly connecting a diode and a predetermined element through a via hole, an inductance component generated by the connection wiring can be reduced, and a high-frequency composite component in which leakage of a transmission signal to the reception circuit side is reduced is provided. it can.

1 is an equivalent circuit diagram of a first embodiment of a high-frequency composite component according to the present invention. It is explanatory drawing which shows the electrode shape formed in each sheet | seat layer (1st-3rd layer from the bottom) of the multilayer substrate of 1st Example. It is explanatory drawing which shows the electrode shape formed in each sheet | seat layer (4th-6th layer from the bottom) of the multilayer substrate of 1st Example. It is explanatory drawing which shows the electrode shape formed in each sheet | seat layer (7th-9th layer from the bottom) of the multilayer substrate of 1st Example. It is explanatory drawing which shows the electrode shape formed in each sheet layer (10th-11th layer from the bottom) of the multilayer substrate of 1st Example. It is explanatory drawing which shows the electrode shape formed in each sheet | seat layer (12th-13th layer from the bottom) of the multilayer substrate of 1st Example. It is principal part sectional drawing of the multilayer substrate of 1st Example. It is a top view which shows the mounting state of each circuit element in the surface of the multilayer substrate of 1st Example. It is a Tx-Rx isolation characteristic figure of the 1st example and a conventional example. It is a block diagram which shows schematic structure of the conventional high frequency composite component.

Hereinafter, embodiments of the high-frequency composite component according to the present invention will be described with reference to the drawings.
(First embodiment)
The high-frequency composite component according to the first embodiment is a so-called quad-band compatible type corresponding to four systems, and an equivalent circuit diagram thereof is shown in FIG.

  Referring to FIG. 1, the high-frequency composite component includes a diplexer 49 connected from an antenna terminal ANT via a capacitor C3. The diplexer 49 branches a DCS / PCS (1800 MHz / 1900 MHz) signal path and a GSM (850 MHz / 900 MHz) signal path. The DCS / PCS system includes a first high frequency switch 41 connected to a diplexer 49, and the first high frequency switch 41 switches between a transmission side and a reception side. A first LC filter 43 is connected to the transmission side of the first high frequency switch 41, and a transmission side terminal 1800 / 1900Tx is further connected via a capacitor C1. The input end of the SAW duplexer 31 is connected to the reception side of the first high frequency switch 41 via the matching circuit 51. A reception-side terminal 1800Rx and a reception-side terminal 1900Rx are connected to the two output terminals of the SAW duplexer 31, respectively.

  Similarly, the GSM system also includes a second high frequency switch 45, a second LC filter 47, a matching circuit 53, a SAW duplexer 33, a transmission side terminal 850 / 900Tx, a reception side terminal 850Rx, and the like.

  Hereinafter, an equivalent circuit of the first high-frequency switch 41 will be described in detail. The connection from the diplexer 49 to the first high frequency switch 41 is branched into two. One is connected to the anode of the diode DD1 connected to the transmission side, and the other is connected to one end of the transmission line DSL2 connected to the reception side.

  The cathode of the diode DD1 connected to the transmission side is connected to the first LC filter 43. A series circuit of an inductor DSLt and a capacitor DCt1 is connected in parallel to the diode DD1. The cathode of the diode DD1 is connected to the ground via the inductor DSL1.

  The other end of the transmission line DSL2 connected to the reception side is connected to the matching circuit 51. The cathode of the diode DD2 is connected between the transmission line DSL2 and the matching circuit 51, and the anode of the diode DD2 is connected to the ground via the capacitor DC5. A resistor Rd is further connected to the anode of the diode DD2, and the other end of the resistor Rd is connected to the ground via a capacitor C5. A control terminal Vc1 is connected between the resistor Rd and the capacitor C5. The transmission / reception signal is switched depending on whether or not a voltage is applied to the control terminal Vc1.

  The direct connection between the diode and the predetermined element by the via hole, which is a feature of the present invention, is shown in FIGS.

  2 to 6 are exploded views of the multilayer substrate constituting the high-frequency composite component according to the first embodiment. Capacitor electrodes and stripline electrodes formed by screen printing or the like on each sheet layer constituting the multilayer substrate. Shows via holes and the like. 2 to 6 are views seen from the other main surface, which is the bottom surface, on the side opposite to the one main surface on which components such as capacitors and diodes are mounted.

  The multilayer substrate is formed by laminating sheets made of ceramics whose main components are barium oxide, aluminum oxide, and silica and firing them at a temperature of 1000 ° C. or lower.

  Various external connection terminal electrodes are formed on the first sheet layer 61a. A ground electrode G1 is formed on the second sheet layer 61b, an electrode DC5a is formed on the third sheet layer 61c, and a ground electrode G2 is formed on the fourth sheet layer 61d. The electrode DC5a of the third sheet layer 61c constitutes a capacitor DC5 with the ground electrodes G1 and G2.

  In the fifth sheet layer 61e to the ninth sheet layer 61i, electrodes DSL2a to DSL2e of the transmission line DSL2 are formed. An antenna electrode ANT is formed on the tenth sheet layer 61j, and a ground electrode G3 is formed on the eleventh sheet layer 61k. A predetermined wiring pattern is formed on the twelfth sheet layer 61l.

  The surface of the thirteenth sheet layer 61m is a surface of a multilayer substrate as shown in FIG. 8, and various connection terminal electrodes are formed thereon. On the surface, SAW duplexer 31, SAW duplexer 33, diodes DD1 and DD2 are mounted, and inductors DSL1 and DSLt, capacitor DCt1, and resistor Rd are mounted.

  FIG. 7 is a cross-sectional view of the main part of the multilayer substrate constituting the high-frequency composite component according to the first embodiment. The diode DD2 is mounted on connection terminal electrodes DD2a and DD2b formed on the surface of the multilayer substrate. In the electrodes DSL2a to DSL2e formed on the fifth sheet layer 61e to the ninth sheet layer 61i, the end portions of the electrodes adjacent to each other between the sheet layers are connected to each other by via holes to form the transmission line DSL2. An end portion of the electrode DSL2e, which is one end side of the transmission line DSL2, is connected to a connection terminal electrode DD2a on which the diode DD2 is mounted by a connection point A. Although not shown, the end of the DSL 2 a that is the other end of the transmission line DSL 2 is connected to the diplexer 49.

  The electrode DC5a, which is one end side of the capacitor DC5, is connected to the connection terminal electrode DD2b on which the diode DD2 is mounted by the connection point B. The ground electrodes G1 and G2, which are the other end side of the capacitor DC5, are connected to each other through via holes, and are further connected to ground electrodes formed on the outer surface of the multilayer substrate through via holes.

  In the connection location A, via holes formed in each of the tenth sheet layer 61j to the thirteenth sheet layer 61m are directly connected to each other. In the connection location B, via holes formed in each of the fourth sheet layer 61d to the thirteenth sheet layer 61m are directly connected to each other.

  Here, the connection point A between the diode DD2 and the transmission line DSL2 and the connection point B between the diode DD2 and the capacitor DC5 shown in the equivalent circuit diagram of FIG. 1 are the connection point A and the connection point B in FIGS. Yes, it can be seen that it consists of direct connection in via holes.

  7 are the connection point A between the diode DD2 and the transmission line DSL2 and the connection point B between the diode DD2 and the capacitor DC5, which are shown in the equivalent circuit diagram of FIG. It shows a direct connection. Similarly, A and B in FIGS. 2 to 6 indicate that the connection points A and B shown in the equivalent circuit diagram of FIG. 1 are directly connected by via holes. For this reason, the connection distance is shortened, and the generated inductance component can be reduced.

In this embodiment, part of the transmission line DSL2 and part of the capacitor DC5 are arranged within the projected area of the diode DD2 in the stacking direction of the multilayer substrate, so that the size of the high-frequency composite component can be reduced. It has become.
The effect of the present embodiment can be explained in the operation of the first high frequency switch 41. When a DCS / PCS (1800 MHz / 1900 MHz) received signal is received from the antenna terminal ANT, the received signal is branched by the diplexer 49 to the first high frequency switch 41 which is a DCS / PCS signal path. At this time, no voltage is applied to the control terminal Vc1. Accordingly, the diodes DD1 and DD2 are in the OFF state, and the signal is transmitted to the reception side terminals 1800Rx and 1900Rx via the matching circuit 51 and the SAW duplexer 31.

  Next, a case where a transmission signal from the transmission side terminal 1800 / 1900Tx is transmitted from the antenna terminal ANT will be described. By applying a positive voltage to the control terminal Vc1, the diodes DD1 and DD2 are turned on. The value of the current flowing through the diode can be controlled by the resistance value of the resistor Rd.

When the diode DD2 is ON, the inductance component possessed by the diode DD2 and the capacitor DC5 constitute a series circuit and have a resonance frequency at a certain frequency. The values of the diode DD2 and the capacitor DC5 are set so that the series resonance frequency matches the frequency of the transmission signal. As a result, the point A which is the cathode of the diode DD2 is grounded at the frequency of the transmission signal. Further, by setting the line length of the transmission line DSL2 to ¼ of the wavelength λ of the transmission signal, it becomes possible to make the impedance on the reception side viewed from the transmission side infinite at the frequency of the transmission signal. High isolation can be achieved.
Here, since the connection from the diode DD2 to the predetermined element is a via hole direct connection at the connection location A and the connection location B, the variation of the inductance component generated at the connection location can be reduced. Since the inductance component generated at the connection point is generated so as to be connected in series to the inductance component of the diode DD2, the variation of the total inductance component is reduced, so that the series resonance frequency is stabilized and Tx is changed to Rx. High isolation can be realized stably.

  In addition, due to the direct connection of via holes, the inductance component itself generated at the connection location is also reduced. Therefore, in the LC series circuit composed of the diode DD2 and the capacitor DC5, when the value is set so that the resonance frequency matches the frequency of the transmission signal, the capacitance component can be increased as much as the inductance component can be reduced.

  Since the inductance component is small and the capacitance component is large, the impedance of the LC series resonance circuit at the resonance frequency is reduced. The effect is shown in the isolation characteristic diagram of FIG. FIG. 9 shows the isolation characteristics between the transmitting side Tx and the matching circuit 51 input section of the receiving side SAW duplexer 31. FIG. 9A is obtained when the connection point A between the diode DD2 and the transmission line DSL2 and the connection point B between the diode DD2 and the capacitor DC5 are directly connected, that is, in this embodiment. FIG. FIG. 9B is a characteristic diagram when the portion is connected to the wiring electrode, that is, in the conventional example.

  In FIG. 9, the horizontal axis indicates the frequency, and the unit is GHz. The vertical axis indicates the attenuation amount of the reception side terminals 1800Rx and 1900Rx as viewed from the transmission side terminals 1800 / 1900Tx, and the unit is dB.

  The points m1, m2, and m3 in FIG. 9A indicate the measurement results at 1.72 GHz, 1.78 GHz, and 1.92 GHz, which were −34.1 dB, −34.8 dB, and −31.0 dB, respectively. Similarly, the points m11, m12, and m13 in FIG. 9B show the measurement results at 1.72 GHz, 1.78 GHz, and 1.92 GHz, respectively, which are −24.4 dB, −28.0 dB, and −20.9 dB, respectively. It was.

The attenuation of FIG. 9A is larger than that of FIG. 9B, and the improvement of the isolation characteristics by the via hole direct connection is clear by comparison.
The diode DD2 is mounted on the electrode formed on the one main surface, but may be directly mounted on the via hole connected to the one main surface.

  In addition, the high-frequency composite component according to the present invention is not limited to the quad-band compatible high-frequency composite component as in the above-described embodiment, but a triple-band compatible high-frequency composite component or a quad-band compatible multi-band compatible component. The same effect can be obtained in the high-frequency composite component.

31, 33 ... SAW duplexer 41, 45 ... high frequency switch 43, 47 ... LC filter 49 ... diplexer 51, 53 ... matching circuit 71 ... multilayer substrate ANT ... antenna terminal 850 / 900Tx, 1800 / 1900Tx ... transmission side terminal 850Rx, 900Rx, 1800Rx, 1900Rx ... reception side terminals Vc1, Vc2 ... control terminals

Claims (2)

A multilayer substrate in which dielectric layers and conductive films are alternately stacked; an electrode formed on one main surface of the multilayer substrate; a diode mounted on the electrode; and the conductive film in the multilayer substrate. A high-frequency composite component comprising a high-frequency switch having a formed capacitor and transmission line, and a ground electrode formed on the outer surface of the multilayer substrate,
One end of the capacitor is connected to the ground electrode, the other end is connected to the anode of the diode, and the transmission line is connected to the cathode of the diode at one end.
The diode is mounted on a pair of electrodes, one end side of the transmission line is disposed directly below the electrode on one side, and an electrode on the other end side of the capacitor is disposed directly below the electrode on the other side. And the connection of the capacitor and the connection of the diode and the transmission line are directly connected only via holes ,
At least a part of the capacitor and the conductive film forming the transmission line is disposed within a projected area of the diode mounted on one main surface of the multilayer substrate in the stacking direction of the multilayer substrate. High frequency composite parts characterized by   2. The high-frequency composite component according to claim 1, wherein the electrode on which the diode is mounted is a tip of the via hole connected to one main surface of the multilayer substrate.

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