JP2004229208A - High frequency switch module - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a high frequency switch module capable of switching connection of a transmitting circuit and an antenna and connection of a receiving circuit and the antenna without integrating a semiconductor switch element into a transmission line where a transmission signal passes. <P>SOLUTION: In a transmission line for transmission of which the one terminal is connected to the antenna and the other terminal is connected to a transmitting circuit terminal is equipped with a semiconductor switching circuit which is connected between the transmitting circuit terminal and a ground and of which the one terminal is connected to the transmission line for transmission and the other terminal is grounded, and the semiconductor switching circuit is configured to transmit the transmission signal from the transmitting circuit terminal through the transmission line for transmission to the antenna. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
TECHNICAL FIELD The present invention relates to a high-frequency switch module that can be used in a mobile radio communication device such as a portable mobile radio device and a mobile phone in the microwave field.
[0002]
[Prior art]
A high-frequency switch module of this type using a PIN diode is known. For example, as shown in FIG. 6, a first circuit in which an anode is connected to a transmission circuit terminal Tx and a cathode is connected to an antenna terminal ANT. , A first phase shifter P1 connected between the anode of the first diode D1 and the ground (ground), and a second phase connected between the antenna ANT and the receiving circuit terminal Rx. It comprises a device P2, a second diode D2 having an anode connected to the receiving circuit terminal Rx side and a cathode connected to the ground side, and a DC cut capacitor (see Patent Document 1).
[0003]
Another conventional high-frequency switch module uses a GaAs switch. FIG. 7 shows a circuit configuration of a dual-band front-end module, which branches or couples an antenna ANT and GSM and DCS. A GaAs switch SW1 that is incorporated in a duplexer DIP and a GSM transmission circuit and switches between a GSM transmission signal and a reception signal, and a GaAs switch SW2 that is incorporated in a DCS transmission circuit and switches between a DSC transmission signal and a reception signal. And The duplexer DIP basically includes an inductor element and a capacitor. For example, the GaAs switch SW1 for GSM connects the antenna terminal side to the GSM transmission circuit terminal Tx side during transmission, and connects the antenna terminal side to the GSM reception circuit terminal Rx side during reception. (See Non-Patent Document 1).
[0004]
[Patent Document 1]
JP-A-10-56301 (Page 2, column 1, column 0002 to page 2, column 2, 0004, FIGS. 3 and 4)
[Non-patent document 1]
Magazine IEEE Radio Frequency Integrated Circuits System Vol. 2001 PP213-216
[0005]
[Problems to be solved by the invention]
In both the conventional high-frequency switch module using a PIN diode as shown in FIG. 6 and the conventional high-frequency switch module using a GaAs switch as shown in FIG. 7, the semiconductor switching element is a transmission circuit (a transmission circuit or a reception circuit). ), The passing signal passes through the semiconductor switch element, which causes a problem that transmission loss increases and harmonic noise (harmonics) occurs.
[0006]
In a conventional high-frequency switch module using a PIN diode as shown in FIG. 6, a large number of components, and generally, first and second phase shifters are provided inside a multilayer substrate, and a first diode and a second phase shifter are provided. Diodes are mounted on a multilayer substrate, and capacitors and resistors are mounted inside the multilayer substrate or mounted as chip components on the multilayer substrate. As a result, the number of components in the inner layer in the multi-layer substrate is increased, and there is a problem that miniaturization is difficult.
[0007]
Therefore, the present invention solves the above-mentioned problem, and allows the transmission circuit and the antenna to be connected to each other without incorporating a semiconductor switch element into a transmission circuit (transmission circuit or reception circuit) through which the transmission signal (transmission signal or reception signal) passes. It is an object of the present invention to provide a high-frequency switch module capable of switching connection and connection between a receiving circuit and an antenna.
[0008]
[Means for Solving the Problems]
In order to achieve the above object, according to a first aspect of the present invention, a high-frequency switch module for switching connection between a transmission circuit and an antenna and connection between a reception circuit and an antenna is provided.
A transmission line having one end connected to the antenna terminal and the other end connected to the transmission circuit terminal;
A semiconductor switching circuit connected between the transmission circuit terminal and ground, one terminal connected to the transmission line for transmission, and the other terminal grounded,
The semiconductor switching circuit is configured to transmit the transmission signal from the transmission circuit terminal to the antenna via the transmission line for transmission.
[0009]
The semiconductor switching circuit may preferably include a GaAs switching element and a capacitor connected to another terminal.
[0010]
In the high-frequency switch module according to the second aspect of the present invention, in addition to the configuration of the first aspect,
A receiving transmission line having one end connected to the antenna terminal and the other end connected to the receiving circuit terminal;
It has another semiconductor switching circuit connected between the receiving circuit terminal and the ground electrode, connecting one terminal to the receiving transmission line, and grounding the other terminal,
The semiconductor switching circuit and another semiconductor switching circuit are characterized in that they are configured to selectively transmit a transmission or reception signal through a transmission transmission line or a reception transmission line.
[0011]
In the second invention, another semiconductor switching circuit may preferably be composed of a GaAs switch element and a capacitor connected to another terminal.
[0012]
In the high frequency switch module according to the third aspect of the present invention,
A transmission line having one end connected to the antenna terminal and the other end connected to the transmission circuit terminal;
A receiving transmission line having one end connected to the antenna terminal and the other end connected to the receiving circuit terminal;
Having a semiconductor switching circuit connected between the transmission circuit terminal and the reception circuit terminal,
The semiconductor switching circuit is configured to selectively transmit a transmission or reception signal through a transmission transmission line or a reception transmission line.
[0013]
In this case, the semiconductor switching circuit is connected to the first terminal connected between the transmission line for transmission and the transmission circuit terminal, the second terminal connected between the transmission line for reception and the reception circuit terminal, and to the ground. It can be composed of a GaAs switch element having a third terminal and a capacitor connected to the third terminal.
[0014]
In the first, second, and third inventions, preferably, the transmission line for transmission and the transmission line for reception may be a line having a length of λ / 4, where λ is the wavelength of the transmission signal.
[0015]
In the high-frequency switch module according to the fourth aspect of the present invention, one end is connected to the antenna terminal, the other end is connected to a transmission line for transmission connected to the transmission circuit terminal, and one end is connected to the antenna terminal, and the other end is connected to the reception circuit. A transmission line for reception connected to the terminal is formed in the multilayer substrate, and a semiconductor switching circuit for selectively transmitting a transmission or reception signal through the transmission line for transmission or the transmission line for reception is a GaAs switch element and the like. And a capacitor connected to the terminal, wherein the capacitor is formed in the multilayer substrate, and the GaAs switch element is mounted on the surface of the multilayer substrate.
[0016]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.
FIG. 1 shows a circuit configuration of a high-frequency switch module according to an embodiment of the present invention. In FIG. 1, ANT is an antenna terminal, Tx is a transmitting circuit terminal, and Rx is a receiving circuit terminal. A transmission line 1 for transmission is provided between the antenna terminal ANT and the transmission circuit terminal Tx, and a transmission line 2 for reception is provided between the antenna terminal ANT and the reception circuit terminal Rx. The transmission line for transmission 1 is configured to have a length of λ / 4, where λ is the wavelength of the received signal. On the other hand, the receiving transmission line 2 is configured to have a length of λ / 4, where λ is the wavelength of the transmission signal.
[0017]
In FIG. 1, reference numerals 3 and 4 denote single pole single throw (SPST) GaAs switch elements constituting a semiconductor switching circuit. One terminal of the GaAs switch element 3 is connected to the transmission circuit terminal Tx, and the other terminal Are grounded via a capacitor 5. Similarly, one terminal of the GaAs switch element 4 is connected to the receiving circuit terminal Rx, and the other terminal is grounded via the capacitor 6.
[0018]
When the transmission signal is transmitted from the transmission circuit terminal Tx to the antenna terminal ANT through the transmission line 1 for transmission in the operation of the circuit of the high-frequency switch module shown in FIG. 1 thus configured, the GaAs switch element 3 is opened. And the GaAs switch element 4 is short-circuited. As a result, the receiving transmission line 2 is grounded via the capacitor 6, the impedance of the receiving transmission line 2 as viewed from the transmitting circuit terminal Tx side becomes infinite, and the transmission circuit terminal Tx passes through the transmitting transmission line 1 to the antenna. A transmission signal is transmitted to the terminal ANT.
[0019]
Conversely, when transmitting a reception signal from the antenna terminal ANT to the reception circuit terminal Rx through the reception transmission line 2, the GaAs switch element 3 is short-circuited and the GaAs switch element 4 is opened. As a result, the transmission line 1 for transmission is grounded via the capacitor 5, the impedance of the transmission line 1 for transmission as viewed from the antenna terminal ANT side becomes infinite, and the terminal of the transmission circuit passes through the transmission line 2 for reception from the antenna terminal ANT. The received signal is transmitted to Rx.
[0020]
FIG. 2 shows a circuit configuration of a high-frequency switch module according to another embodiment of the present invention. In FIG. 2, portions corresponding to the circuit in FIG. 1 are denoted by the same reference numerals. In the circuit configuration of the high-frequency switch module shown in FIG. 2, a single-pole, double-throw (SPDT) GaAs switch element 7 is used. As shown, the GaAs switch element 7 has a transmission circuit terminal Tx and a reception circuit terminal Rx. Connected between That is, the first terminal 7a of the GaAs switch element 7 is connected between the transmission line 1 for transmission and the transmission circuit terminal Tx, and the second terminal 7b is connected between the transmission line 2 for reception and the reception circuit terminal Rx. The third terminal 7c is grounded via a capacitor 8.
[0021]
When the first terminal 7a of the GaAs switch element 7 is short-circuited in the operation of the circuit of the high-frequency switch module shown in FIG. 2 configured as described above, the transmission line 1 for transmission is grounded via the capacitor 8 and is connected from the antenna terminal ANT side. The impedance of the transmission line 1 for transmission becomes infinite, and the reception signal is transmitted from the antenna terminal ANT to the reception circuit terminal Rx through the transmission line 2 for reception. On the other hand, when the first terminal 7b of the GaAs switch element 7 is short-circuited, the receiving transmission line 2 is grounded via the capacitor 8, the impedance of the receiving transmission line 2 as viewed from the transmitting circuit terminal Tx side becomes infinite, and the transmitting circuit A transmission signal is transmitted from the terminal Tx to the antenna terminal ANT through the transmission line 1 for transmission.
[0022]
FIG. 3 is a schematic exploded perspective view showing a structure formed on a laminate of the high-frequency switch module having the circuit configuration shown in FIG. The illustrated high-frequency switch module is formed on a multilayer substrate 17 composed of six layers of dielectric substrates 11, 12, 13, 14, 15, and 16. One ground electrode 8a of the capacitor 8 is formed on the front surface of the first dielectric substrate 11, and pads constituting the antenna terminal ANT, the ground terminal GND, the transmission circuit terminal Tx, and the reception circuit terminal Rx are formed on the rear surface. Have been.
[0023]
On the surface of the second dielectric substrate 12, the other electrode 8b of the capacitor 8 is formed. A ground electrode G1 is formed on the surface of the third dielectric substrate 13, and a transmission line 1 for transmission and a transmission line 2 for reception are formed continuously on the surface of the fourth dielectric substrate 14. A connection pad CON connected to the antenna terminal ANT is formed at an intermediate point between the transmission lines 1 and 2. A ground electrode G2 is formed on the surface of the fifth dielectric substrate 15, and a pad P for mounting the GaAs switch element 7 is formed in the center of the surface of the sixth dielectric substrate 16. The ground terminal GND, the electrode terminal T1 connected to the other electrode 8b of the capacitor 8, the transmission circuit terminal Tx, the reception circuit terminal Rx, and the GaAs switch element are provided around the surface of the sixth dielectric substrate 16. 7, a pad constituting an operation control terminal T3 of the GaAs switch element 7 and a drive power supply terminal T2 of the GaAs switch element 7 are formed. The connection between the GaAs switch element 7 and each pad is performed by wire bonding.
[0024]
The circuit elements formed on each substrate are connected between predetermined substrates by via holes (not shown) as schematically shown by dotted lines in FIG. Then, the respective substrates are laminated as shown in FIG. 4 to form a laminated structure of the high-frequency switch module.
[0025]
In the present invention, the GaAs switch element 7 is mounted on the multilayer substrate. However, as shown in FIG. 5, a structure in which a concave portion is provided in the multilayer substrate 17 and the GaAs switch element 7 is disposed in the concave portion may be adopted. With such a structure, the height of the high-frequency switch module can be further reduced.
[0026]
In the present invention, a λ / 4 line is used as the transmission transmission line and the reception transmission line, but a low-pass filter including an inductor element and a capacitor may be used.
[0027]
【The invention's effect】
As described above, in the high-frequency switch module according to the first and second aspects of the present invention, since the transmission signal is configured not to pass through the semiconductor switching circuit, transmission loss can be suppressed low. Distortion can be suppressed low, that is, generation of harmonics can be suppressed.
[0028]
Further, when a GaAs switch element is used in the semiconductor switching circuit, the current consumption can be reduced as compared with the case where a conventional PIN diode is used, and stable operation can be performed for a long period of time.
[0029]
In the high-frequency switch module according to the third aspect of the present invention, since one semiconductor switching circuit is provided between the transmission circuit terminal and the reception circuit terminal, the number of components to be used is reduced in addition to the above effects. And cost can be reduced.
[0030]
In the high-frequency switch module according to the fourth aspect of the present invention, the number of circuit elements used can be reduced as compared with the conventional structure, so that the mounting area can be reduced, and as a result, the size can be reduced.
[Brief description of the drawings]
FIG. 1 is a schematic block diagram showing a circuit configuration of a high-frequency switch module according to an embodiment of the present invention.
FIG. 2 is a schematic block diagram showing a circuit configuration of a high-frequency switch module according to another embodiment of the present invention.
FIG. 3 is a schematic exploded perspective view showing a configuration of a laminated structure in the high-frequency switch module shown in FIG. 2;
FIG. 4 is a schematic perspective view of the laminated structure of FIG. 3;
FIG. 5 is a schematic cross-sectional view showing a modified example of the dielectric laminated structure in the high-frequency switch module.
FIG. 6 is a block diagram showing an example of a circuit configuration of a conventional high-frequency switch module.
FIG. 7 is a block diagram showing another example of the circuit configuration of the conventional high-frequency switch module.
[Explanation of symbols]
ANT: antenna terminal Tx: transmission circuit terminal Rx: reception circuit terminal 1: transmission transmission line 2: reception transmission line 3: GaAs switch element 4: GaAs switch element 5: capacitor 6: capacitor 7: GaAs switch element 8: capacitor 17: Multilayer substrate

Claims (10)

In a high-frequency switch module that switches the connection between the transmission circuit and the antenna and the connection between the reception circuit and the antenna,
A transmission line having one end connected to the antenna terminal and the other end connected to the transmission circuit terminal;
A semiconductor switching circuit connected between the transmission circuit terminal and ground, having one terminal connected to the transmission line for transmission, and the other terminal grounded,
A high-frequency switch module, wherein the semiconductor switching circuit is configured to transmit a transmission signal from a transmission circuit terminal to an antenna through a transmission line for transmission. 2. The high-frequency switch module according to claim 1, wherein the semiconductor switching circuit comprises a GaAs switch element and a capacitor connected to another terminal. The high-frequency switch module according to claim 1, wherein the transmission line is a λ / 4 line. In a high-frequency switch module that switches the connection between the transmission circuit and the antenna and the connection between the reception circuit and the antenna,
A transmission line having one end connected to the antenna terminal and the other end connected to the transmission circuit terminal;
A receiving transmission line having one end connected to the antenna terminal and the other end connected to the receiving circuit terminal;
A semiconductor switching circuit connected between the transmission circuit terminal and ground, one terminal connected to the transmission line for transmission, and the other terminal grounded;
Another semiconductor switching circuit connected between the receiving circuit terminal and the ground, connecting one terminal to the receiving transmission line, and grounding the other terminal,
A high-frequency switch module, wherein the semiconductor switching circuit and another semiconductor switching circuit are configured to selectively transmit a transmission or reception signal through a transmission transmission line or a reception transmission line. 5. The high-frequency switch module according to claim 4, wherein the semiconductor switching circuit and another semiconductor switching circuit include a GaAs switch element and a capacitor connected to another terminal. The high-frequency switch module according to claim 4, wherein the transmission transmission line and the reception transmission line are λ / 4 lines. In a high-frequency switch module that switches the connection between the transmission circuit and the antenna and the connection between the reception circuit and the antenna,
A transmission line having one end connected to the antenna terminal and the other end connected to the transmission circuit terminal;
A receiving transmission line having one end connected to the antenna terminal and the other end connected to the receiving circuit terminal;
Having a semiconductor switching circuit connected between the transmission circuit terminal and the reception circuit terminal,
A high-frequency switch module, wherein the semiconductor switching circuit is configured to selectively transmit a transmission or reception signal through a transmission transmission line or a reception transmission line. A semiconductor switching circuit includes a first terminal connected between the transmission line for transmission and the transmission circuit terminal, a second terminal connected between the transmission line for reception and the reception circuit terminal, and a third terminal connected to ground. The high frequency switch module according to claim 7, comprising a GaAs switch element provided and a capacitor connected to the third terminal. The high-frequency switch module according to claim 7, wherein the transmission transmission line and the reception transmission line are λ / 4 lines. One end is connected to the antenna terminal, the other end is connected to the transmission circuit terminal, and the transmission line for transmission is connected to the antenna terminal, and the other end is connected to the reception circuit terminal. A semiconductor switching circuit formed and selectively transmitting a transmission or reception signal through a transmission transmission line or a reception transmission line comprises a GaAs switch element and a capacitor connected to another terminal, and the capacitor is a multilayer substrate. Wherein the GaAs switch element is mounted on the surface of the multilayer substrate.

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