JP3307201B2 - High frequency switch - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a high-frequency switch for switching a signal path in a high-frequency circuit such as a portable telephone, and more particularly to a high-frequency switch having four ports and using a distributed constant line.

[0002]

2. Description of the Related Art In general, in a portable telephone, two antennas, or one antenna and one external connection terminal, may be commonly used by a transmitting unit and a receiving unit. In such a configuration, for example, a switch circuit shown in FIG. 6 is conventionally used.

The switch circuit 51 has a configuration in which three-port switches 52 and 53 are connected. The switch 52
It has a first port P21, a second port P22, and a third port P23. Similarly, the switch 53 is
It has third ports P31, P32 and P33. The antenna ANT is connected to the first port P21 of the switch 52, and the third port P23 is connected to the external connection terminal EXT.
It has been. In addition, as an example of using as an external connection terminal, there is a case where a predetermined signal is input from the external connection terminal when measuring the electrical characteristics of the receiving unit of the mobile phone in which the switch circuit 51 is built. Also, the third
Port P23 may be connected to a second antenna. That is, in an in-vehicle mobile phone or the like, an antenna mounted on a vehicle can be connected and used as the second antenna.

In the switch 52, a second port P
22 is the first port P21 or the third port P23
Is configured to be able to be switched over. The second port P22 is connected to the second port P32 of the switch 53.

[0005] The second port P32 of the switch 53 is configured so that the connection can be switched between a first port P31 and a third port P33. The first port P31 is connected to the transmission unit Tx, and the third port P33
Is connected to the receiving unit Rx.

By using the switch circuit 51, it is possible to realize a state in which one of the antenna ANT and the external connection terminal EXT is connected to the transmitting unit Tx or the receiving unit Rx.

By the way, the three-port switch 52,
A high-frequency switch using a diode shown in FIG. The high frequency switch 60 is connected to the first to third ports P21 to P2.
3, first to third ports P6 corresponding to P31 to P33
1 to P63. The first port P61 is connected to the anode of the diode 62a via the capacitor 61a. The anode of the diode 62a is connected to the ground potential via a distributed constant line 63a acting as a choke coil and a capacitor 61b, and the connection point between the distributed constant line 63a and the capacitor 61b is connected to a control voltage terminal 65a via a resistor 64a. You. A control circuit (not shown) for switching the high-frequency switch 60 is connected to the control voltage terminal 65a. The cathode of the diode 62a is
Connected to second port P62 via capacitor 61c.

Further, a distributed constant line 63b is connected to the second port P62 via a capacitor 61c. The distributed constant line 63b is connected to the third port P63 via the capacitor 61d, and the connection point between the distributed constant line 63b and the capacitor 61d is connected to the anode of the diode 62b. The cathode of diode 62b is connected to ground potential via capacitor 61e, and is connected to control voltage terminal 65b via resistor 64b. A control circuit (not shown) for switching the high frequency switch 60 is connected to the control voltage terminal 65b. Note that the distributed constant lines 63a and 63b are composed of strip lines, microstrip lines, and coplanar guidelines having a length of λ / 4 or less, where λ is the wavelength of the high-frequency signal flowing through the switch 61. Also,
The distributed constant line 63a may be formed of a high impedance transmission line.

In the high frequency switch 60, the control voltage terminal 6
5a and the control voltage terminal 65b are applied with different control voltages, so that the second port P62 is connected to the first port P61 or the third port P63
Can be realized. For example, when a positive control voltage is applied to the control voltage terminal 65a and a negative control voltage is applied to the control voltage terminal 65b, these voltages become
Since the diodes 62a and 62b act as forward bias voltages, the diodes 62a and 62b are turned on. At this time, the capacitors 61a, 61b, 61c, 6
The direct current is cut by 1d and 61e, and the control current is applied only to the circuit including the diodes 62a and 62b. Accordingly, since the distributed constant line 63b is grounded by the diode 62b and resonates at the frequency of the high-frequency signal to be used, and the impedance becomes almost infinite, the high-frequency signal from the first port P61 is transmitted to the third port P63 side. Is transmitted to the second port P62 via the capacitor 61a, the diode 62a, and the capacitor 61c without being transmitted to the second port P62. Since the distributed constant line 63a is grounded by the capacitor 61b, it resonates at the frequency of the high frequency signal, the impedance becomes almost infinite, and the high frequency signal is prevented from leaking to the ground potential side.

On the other hand, when a negative control voltage is applied to the control voltage terminal 65a and a positive control voltage is applied to the control voltage terminal 65b, these voltages are applied to the diodes 62a and 62b, contrary to the above case. Diodes 62a and 62b are turned off, and the high frequency signal from the third port P63 is transmitted to the second port P62 via the capacitor 61d, the distributed constant line 63b, and the capacitor 61c. Is hardly transmitted to the first port P61 side.

As described above, in the high-frequency switch 60, by applying the positive and negative control voltages to the control voltage terminals 65a and 65b, the second port P62 is connected to the first port P61 or the third port P63. Can be realized.

The switch circuit 51 shown in FIG.
The high-frequency switch 60 is used as the switches 52 and 53. That is, two 3-port high-frequency switches are used, and the first ports are connected to each other.

[0013]

The switch circuit 51 includes:
As described above, since the high-frequency signal is configured by connecting the two high-frequency switches 52 and 53, the high-frequency signal passes through the two switches. For example, the transmission unit Tx
The transmission output provided from the first and second antennas passes through the two switches 53 and 52 before being applied to the antenna ANT. Similarly, the high-frequency signal input from the antenna ANT passes through the switches 52 and 53 and is provided to the receiving unit Rx. For this reason, the insertion loss must be large (about twice), so that it is necessary to increase the transmission output at the time of transmission, and to reduce the gain at the time of reception.

In the switch circuit 51, since the switches 52 and 53 are formed using the high-frequency switch 60, a control voltage must be applied to two control voltage terminals in each of the switches 52 and 53. Each switch 52, 53 requires two control voltage supply power supplies. As a result, a complicated wiring pattern for a power supply had to be formed on the circuit board.

SUMMARY OF THE INVENTION An object of the present invention is to solve such a problem and to reduce the insertion loss, reduce the number of components, and simplify the wiring pattern for supplying the control voltage. It is an object of the present invention to provide a high-frequency switch.

[0016]

In order to solve the above-mentioned problems, the present invention has first to fourth ports, and connects the first and second ports to a third or fourth port. A high-frequency switch comprising: a first switch connected between the first and third ports; a third switch connected between the second ports; a second switch connected between the fourth ports; and a fourth switch connected between the first ports. A distributed constant line, diodes respectively connected between the first to fourth ports and a reference potential, and distributed constants connected between at least one of the first to fourth ports and a reference potential A line, first to fourth control voltage terminals connected to a connection point between the diode and a reference potential, and a connection between at least one of the first to fourth ports and a reference potential; Fixed voltage connected to the connection point between the distributed constant line and the reference potential Characterized in that it comprises a pin.

Further, at least one of the first to fourth control voltage terminals and the fixed voltage terminal is connected to each connection point via a resistor.

Further, at least one of the first to fourth ports is connected to a reference potential via a capacitor.

Further, the semiconductor device is characterized in that a resistor is provided in parallel with at least one of the diodes.

[0020] Further, the invention is characterized in that a distributed constant line and a capacitor are connected in parallel to at least one of the diodes and connected in series with each other.

Further, a series circuit of a distributed constant line and a capacitor is connected in parallel with at least one of the diodes, and a capacitor is connected in parallel with a series circuit of the distributed constant line and the capacitor. Features.

According to the high frequency switch of the present invention, first,
The third port, the third and second ports, the second and fourth ports, and the fourth and first ports are respectively connected by a first distributed constant line. Also, the distributed parameter line is
Configure the ring-shaped circuit part connected as described above,
Since the first to fourth ports are connected as described above, the first port is arranged along the circumferential direction of the ring-shaped circuit portion.
Each port is connected in the order of a third port, a second port, and a fourth port, and is connected to a reference potential via a diode. Further, first to fourth control voltage terminals are connected to a connection point between the diode and the reference potential.

Therefore, by applying the control voltage and the fixed voltage to the first to fourth control voltage terminals and the fixed voltage terminal, the distributed constant line between the first to fourth ports is turned on, and , A state in which the third port is connected (first connection state), a state in which the first and fourth ports are connected (second connection state), and a state in which the second and third ports are connected (Third connection state) or a state where the second and fourth ports are connected (fourth connection state).

[0024]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a schematic circuit diagram for explaining an embodiment of the high-frequency switch according to the present invention. High frequency switch 1
Is a four-port high-frequency switch having first to fourth ports P1 to P4. First and third ports P1, P3
, Between the first and fourth ports P1 and P4, between the second and third ports P2 and P3, and between the second and fourth ports P2 and P4, so as to perform switching. , 2
b, 2c and 2d are connected. That is, the distributed constant lines 2a to 2d are connected in a ring shape.

In the high-frequency switch 1, the following first connection state to fourth connection state are realized, and it is possible to switch between these connection states. In the first connection state, the first and third ports P1 and P3 are connected, and in the second connection state, the first and fourth ports P1 and P3 are connected.
In the third connection state, the second and third ports P2 and P3 are connected, and in the fourth connection state, the second and fourth ports P2 and P4 are connected. The state is realized.

Therefore, the high-frequency switch 1 of this embodiment can be suitably used for the high-frequency switch circuit 51 of FIG. That is, in the high-frequency switch circuit 51 of FIG. 6, the transmitting unit Tx is connected to the antenna ANT (during transmission), and the transmitting unit Tx is connected to the external terminal EXT (when the second antenna is connected to the external terminal EXT). And the like, when the receiving unit Rx is connected to the antenna ANT (during reception), when the external terminal EXT is connected to the receiving unit Rx (when evaluating the performance of the receiving unit or when the external antenna is connected (E.g., reception by connecting to the terminal EXT). High frequency switch 1 of the present embodiment
Is used, the first port P1 is connected to the transmitting unit Tx, for example.
The second port P2 to the receiving unit Rx, and the third port P
The third and fourth ports P4 are connected to the antenna ANT, respectively.
And by connecting the external terminal EXT, it can be used similarly to the high-frequency switch circuit 51.

FIG. 2 is a circuit diagram of an embodiment of the high-frequency switch according to the present invention. In the present embodiment, between the first and third ports P1 and P3, between the first and fourth ports P1 and P4,
Distributed constant lines 2a to 2d are connected between the second and third ports P2 and P3, and between the second and fourth ports P2 and P4. That is, the distributed constant lines 2a to 2d are connected in a ring shape as illustrated.

The first port P1 is connected to distributed constant lines 2a and 2b via a capacitor 3a, and a connection point A between the first port P1 and the distributed constant lines 2a and 2b is connected to a reference potential, that is, a ground potential. , A diode 4a is connected, and a capacitor 3b is connected to the anode side of the diode 4a. One end of a resistor 5a is connected to a connection point B between the diode 4a and the capacitor 3b, and the other end of the resistor 5a is connected to a first control voltage terminal Vc1.

Similarly, the second port P2 is connected to the distributed constant lines 2c and 2d via the capacitor 3c,
Connection point C between the port P2 and the distributed constant lines 2c and 2d
And a ground potential, a diode 4b is connected, and a capacitor 3d is connected to the anode side of the diode 4b. One end of the resistor 5b is connected to a connection point D between the diode 4b and the capacitor 3d, and the other end is connected to the second node.
Is connected to the control voltage terminal Vc2.

Similarly, the third port P3 is connected to the distributed constant lines 2a and 2c via the capacitor 3e,
Connection point E between the port P3 and the distributed constant lines 2a and 2c
And a ground potential, a diode 4c is connected, and a capacitor 3f is connected to the anode side of the diode 4c. One end of a resistor 5c is connected to a connection point F between the diode 4c and the capacitor 3f, and the other end is connected to a third terminal.
Is connected to the control voltage terminal Vc3.

Similarly, the fourth port P4 is connected to distributed constant lines 2b and 2d via a capacitor 3g,
Connection point G between the port P4 and the distributed constant lines 2b and 2d
And a ground potential, a diode 4d is connected, and a capacitor 3h is connected to the anode side of the diode 4d. One end of a resistor 5d is connected to a connection point H between the diode 4d and the capacitor 3h, and the other end is connected to the fourth
Is connected to the control voltage terminal Vc4.

Further, a distributed constant line 6 is connected in parallel with the diode 4b between a connection point C between the second port P2 and the distributed constant lines 2c and 2d and a ground potential. The capacitor 3i is connected to the ground potential side. One end of a resistor 5e is connected to a connection point I between the distributed constant line 6 and the capacitor 3i, and the other end is connected to a fixed voltage terminal Vfix.

At this time, the distributed constant lines 2a to 2d and 6
Is composed of a stripline, a microstripline, a coplanar guideline, and the like having a length of λ / 4 or less, where λ is a wavelength of a high-frequency signal flowing through the high-frequency switch 1. The distributed constant lines 2a to 2d and 6 are so-called λ / 4 lines, but actually have a length of λ / 4 or less as described above because of the influence of the inductance of the strip line and the stray capacitance. It is composed of

Next, the operation of the high-frequency switch 1 will be described. Table 1 shows the relationship between the direction of the diodes 4a to 4d, the control voltages of the first to fourth control voltage terminals Vc1 to Vc4 and the fixed voltage terminal Vfix, and the operation between the ports.

[0035]

[Table 1]

Here, the case of realizing the first connection state will be described. Second and fourth control voltage terminals Vc2, Vc
A positive control voltage + Vcc is applied to c4, and a ground potential, that is, 0 [V] is applied to the first and third control voltage terminals Vc1 and Vc3 and the fixed voltage terminal Vfix. In this case, the control voltage supplied from the second control voltage terminal Vc2 is dropped by the resistors 5b and 5e, and is applied to the diode 4b as a forward bias voltage. Similarly, a voltage obtained by subtracting the voltage drop by the resistors 5d and 5e from the control voltage given from the fourth control voltage terminal Vc4 is applied to the diode 4d as a forward bias voltage. Therefore, the diodes 4b and 4d are turned on, and the series circuit of the diode 4b and the capacitor 3d and the diode 4d
And the impedance of the series circuit of the capacitor 3h becomes zero, and the connection points C and G are short-circuited to the ground potential.

On the other hand, the connection point I is connected to the fixed voltage terminal Vfix via the resistor 5e.
With respect to a, a reverse bias is applied by a voltage drop in the resistor 5e. Similarly, a reverse bias is applied to the diode 4c by the voltage drop in the resistor 5e. Accordingly, the diodes 4a and 4c are turned off, and the capacitance of the series circuit of the diode 4a and the capacitor 3b and the series circuit of the diode 4c and the capacitor 3f can be maintained.

Here, the distributed constant lines 2a to 2d and 6
Is designed to operate as an impedance inverting circuit at the operating frequency, and since the connection points C and G are short-circuited to the ground potential, the distributed constant lines 2b, 2c and 6 are connected from the connection points A and E, respectively. Looking at the side, its impedance is infinite. Therefore, the connection points A and E are connected, and the connection points C and G are short-circuited to the ground potential, so that only the first and third ports P1 and P3 are turned on.

To realize the second to fourth connection states, control voltages as shown in Table 1 are applied to the first to fourth control voltage terminals Vc1 to Vc4 and the fixed voltage terminal Vfix. I just need.

As described above, according to the high-frequency switch 1 of this embodiment, a four-port high-frequency switch can be configured.

A high-frequency signal flowing between a pair of ports flows only through one distributed constant line connected between the pair of ports. Therefore, the insertion loss can be halved compared to the conventional high-frequency switch circuit, and the life of the elements constituting the high-frequency switch can be extended. In addition, for example, when used for mobile phones,
It is possible to reduce battery consumption and extend the talk time and standby time.

Further, the first and second ports are symmetric with respect to the connection to the third and fourth ports.
Therefore, it can be suitably used as a changeover switch for a diversity antenna.

Further, among the control voltages applied to the first to fourth control voltage terminals and the fixed voltage terminal, at least two terminals can be set to the ground potential. It is only necessary to apply a voltage, for example a positive or negative control voltage. Therefore, the wiring pattern on the printed board on which the high-frequency switch is mounted can be simplified, and the printed board can be downsized. In addition, it can greatly contribute to miniaturization of electronic equipment in which the high-frequency switch is incorporated.

In the above embodiment, the distributed constant line 6
Is connected to only the connection point C, but the connection may be made to at least one of the connection points A, C, E, and G.

Further, a ground potential may be applied instead of the positive control voltage + Vcc, and a negative control voltage -Vcc may be applied instead of the ground potential. In this case, in the first connection state, the second and fourth control voltage terminals Vc2 and Vc4 are grounded, and the first and third control voltage terminals Vc1 and Vc3 and the fixed voltage terminal Vfix are negative. What is necessary is just to apply the control voltage -Vcc. The same applies to the case where the second to fourth connection states are realized.

Further, in this embodiment, the diodes 4a to 4a
4d was connected in the direction shown in FIG.
May be connected in the opposite direction. That is, the anodes of the diodes 4a to 4d are connected to the connection points A, C, E, G
On the side, the cathodes of the diodes 4a to 4d are connected to a connection point B,
The diodes 4a to 4d may be connected to be on the D, F, and H sides. In this case, the embodiment shown in FIG.
Since the polarity of the diode is reversed, as shown in Table 1,
The voltage applied to the first to fourth control voltage terminals Vc1 to Vc4 and the fixed voltage terminal Vfix may be selected.

The resistors 5a to 5e are connected to the high-frequency switch 1 from the first to fourth control voltage terminals Vc1 to Vc4 and the fixed voltage terminal Vfix via connection points B, D, F, H and I.
Are provided to adjust the values of the first to fourth control voltages and the fixed voltage to be supplied to the connection point B. In some cases, the connection points may not be connected.
D, F, H, and I are directly connected to the first to fourth control voltage terminals Vc1.
To Vc4 and the fixed voltage terminal Vfix.

Further, the capacitors 3a to 3i have a function of cutting a direct current, and may not be connected in some cases.

Next, a first modification of the high frequency switch 1 will be described. As indicated by the dashed line in FIG.
First to fourth ports P1 to P4 and distributed constant lines 2a to 2
The capacitors 7a to 7d may be connected between the connection points A, C, E, and G of d and the reference potential, respectively. In this case, the characteristic impedance can be corrected by selecting the capacitance of the capacitors 7a to 7d,
Thereby, the insertion loss and the reflection loss of the high-frequency switch 1 can be effectively reduced. In addition, the length of the distributed constant line 6 can be shortened, whereby the high-frequency switch 1 can be downsized.

It is not always necessary to use all of the capacitors 7a to 7d, and only one of them may be connected.

Next, second to fourth modified examples applicable to the high-frequency switch of the above embodiment will be described with reference to FIGS. In the modified examples shown in FIGS. 3 to 5, each of the circuit elements described later is connected to an arbitrary one of the diodes 4a to 4d. 3 to 5, the diodes 4a to 4a
The portion provided in the diode 4a will be described on behalf of 4d.

As shown in FIG. 3, in the second modification, a resistor 8 is connected in parallel with the diode 4a. The diode 4a functions as a DC capacitor when in the off state. Therefore, while in the off state, the accumulated charge flows at the same time when the diode 4a is turned on, but in the configuration shown in FIG.
The accumulated charge is discharged to the resistor 8, and the switching operation of the diode 4a from the off state to the on state is smoothed.
In addition, the reverse bias of the diode when it is off can be stabilized.

In the third modification shown in FIG. 4, a distributed constant line 9 and a capacitor 10 connected in series with each other are connected in parallel with the diode 4a. In this configuration, a parallel resonance circuit is formed by the capacitance in the off state of the diode 4a and the inductance of the distributed constant line 9. Therefore, by adjusting the inductance of the distributed constant line 9 so that the resonance frequency of the parallel resonance circuit matches the frequency of the transmitted high-frequency signal, the off-state impedance of the diode 4a can be increased. As a result, the isolation characteristics of the diode 4a in the off state can be improved. The capacitor 10 is connected to the distributed constant line 9
It is provided to prevent DC from bypassing.

The distributed parameter line 9 is composed of a strip line, a micro strip line, a coplanar guide line, and the like, and its length and impedance are selected so that the resonance frequency of the parallel resonance circuit matches the frequency of the high-frequency signal. .

Further, when the capacitance in the off state of the diode 4a is small and a desired resonance frequency cannot be obtained, as a fourth modification, as shown in FIG. In addition to the connection of the series circuit of the line 9 and the capacitor 10,
Is connected. In this configuration, a parallel resonance circuit is configured by the combined capacitance of the capacitor 4 and the capacitance in the off state of the diode 4a and the inductance of the distributed constant line 9, and a desired resonance frequency can be obtained.

The first to fourth modifications can be combined with each other.

[0057]

According to the high frequency switch of the first aspect, 4
A port-type high-frequency switch can be configured.

A high-frequency signal flowing between a pair of ports flows only through one distributed constant line connected between the pair of ports. Therefore, the insertion loss can be halved compared to the conventional high-frequency switch circuit, and the life of the elements constituting the high-frequency switch can be extended. In addition, for example, when used for mobile phones,
It is possible to reduce battery consumption and extend the talk time and standby time.

Further, the first and second ports are symmetric with respect to the connection to the third and fourth ports.
Therefore, it can be suitably used as a changeover switch for a diversity antenna.

Further, among the control voltages applied to the first to fourth control voltage terminals and the fixed voltage terminal, at least two terminals can be set to the ground potential. It is only necessary to apply a voltage, for example a positive or negative control voltage. Therefore, the wiring pattern on the printed board on which the high-frequency switch is mounted can be simplified, and the printed board can be downsized. In addition, it can greatly contribute to miniaturization of electronic equipment in which the high-frequency switch is incorporated.

According to the high frequency switch of the second aspect, the values of the control voltage and control current at the first to fourth control voltage terminals and the fixed voltage terminal can be easily adjusted by the resistance value of the resistor.

According to the high-frequency switch of the third aspect, the characteristic impedance can be corrected by selecting the capacitance of the capacitor, whereby the insertion loss and the reflection loss can be effectively reduced. In addition, the length of the distributed constant line connected in parallel with the diode can be shortened, whereby the size of the high-frequency switch can be reduced.

According to the high frequency switch of the fourth aspect, the electric charge accumulated in the capacitance when the diode is in the off state is discharged to the resistor connected in parallel with the diode at the same time as the on state. Therefore, the switching operation of the diode from the off state to the on state can be smoothed. In addition, the reverse bias of the diode when it is off can be stabilized.

According to the high frequency switch of the fifth aspect, a parallel resonance circuit is formed by the capacitance in the off state of the diode and the inductance of the distributed constant line connected in parallel with the diode. Therefore, by configuring the resonance frequency of this parallel resonance circuit to match the frequency of the high-frequency signal transmitted to the high-frequency switch,
The off-state impedance of the diode can be increased, and as a result, the isolation characteristics can be improved. In addition, a capacitor connected in series with the distributed constant line can prevent a direct current from being bypassed to a circuit portion including the distributed constant line.

According to the high frequency switch of the sixth aspect, the combined capacitance of the capacitance in the off state of the diode and the capacitor connected in parallel to the diode, and the distribution connected in parallel to the diode and the capacitor. A parallel resonance circuit is formed by the inductance of the constant line. Therefore, a desired resonance frequency can be obtained, and the isolation characteristics can be further improved.

[Brief description of the drawings]

FIG. 1 is a schematic circuit diagram showing a schematic configuration of an embodiment of a high-frequency switch according to the present invention.

FIG. 2 is a circuit diagram of one embodiment of a high-frequency switch according to the present invention.

FIG. 3 is a circuit diagram for explaining a second modification of the high-frequency switch.

FIG. 4 is a circuit diagram for explaining a third modification of the high-frequency switch.

FIG. 5 is a circuit diagram for explaining a fourth modification of the high-frequency switch.

FIG. 6 is a schematic configuration diagram for explaining a conventional high-frequency switch circuit.

FIG. 7 is a circuit diagram showing an example of a conventional three-port high-frequency switch.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 High frequency switch 2a-2d, 6, 9 Distributed constant line 4a-4d Diode 5a-5e, 8 Resistance 7a-7d 10, 11 Capacitor P1-P4 Port Vc1-Vc4 Control voltage terminal Vfix Fixed voltage terminal

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-9-83206 (JP, A) JP-A-6-196724 (JP, A) JP-A-2-117219 (JP, A) JP-A-63- 13418 (JP, A) JP-A-6-197041 (JP, A) JP-A-8-18302 (JP, A) JP-A-51-11549 (JP, A) JP-A-7-263901 (JP, A) JP-A-7-312568 (JP, A) JP-A-3-250807 (JP, A) JP-A-48-108538 (JP, U) JP-B-1-33961 (JP, B2) (58) (Int.Cl. ⁷ , DB name) H01P 1/15 H03K 17/76 H04B 1/44

Claims (6)

(57) [Claims] 1. A high-frequency switch having first to fourth ports, wherein the first and second ports are connected to a third or fourth port, wherein the first and third ports are connected to each other. Distributed constant lines connected between ports, between third and second ports, between second and fourth ports, and between fourth and first ports, respectively, and the first to fourth ports and a reference potential , A distributed constant line connected between at least one of the first to fourth ports and a reference potential, and a connection point between the diode and the reference potential. The first to fourth control voltage terminals and a connection point between a distributed constant line connected between at least one of the first to fourth ports and a reference potential and the reference potential. A high-frequency switch comprising a fixed voltage terminal. 2. The high-frequency switch according to claim 1, wherein at least one of the first to fourth control voltage terminals and the fixed voltage terminal is connected to each connection point via a resistor. 3. The high-frequency switch according to claim 1, wherein at least one of the first to fourth ports is connected to a reference potential via a capacitor. 4. The high-frequency switch according to claim 1, further comprising a resistor connected in parallel to at least one of the diodes. 5. The method according to claim 1, further comprising a distributed constant line and a capacitor connected in parallel to at least one of the diodes and connected in series with each other. The high frequency switch as described. 6. A series circuit of a distributed constant line and a capacitor is connected in parallel with at least one of the diodes,
The high-frequency switch according to any one of claims 1 to 4, wherein a capacitor is connected in parallel with a series circuit of the distributed constant line and the capacitor.