JPH05299995A - Micro wave semiconductor switch - Google Patents

Abstract

PURPOSE:To improve an isolation characteristic between terminals, and a processable transmission power by specifying the values of an inductor and a capacitor loaded on or serially connected with plural semiconductor switches, and specifying an operational frequency. CONSTITUTION:A circuit in which a semiconductor switch element 20a is serially connected with an inductor L, is connected in parallel with a circuit in which a semiconductor switch element 20b on whose both edges an inductor L' is loaded is serially connected with a capacitor C. The switch elements 20a and 20b are interlocked so that one can be turned-on when the other is turned on. Then, when a parasitic capacitor between both the terminals 100 and 101 of the switch elements 20a and 20b is defined as Cs, the values of the inductors L and L', and the capacitor C are set so that an expression I can be fulfilled, and an expression II is fulfilled for an operational frequency (f). Thus, the switching of a conduction/opening can be attained by the same frequency, and a high isolation can be realized in a micro wave area.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a microwave semiconductor switch that conducts / opens a signal propagation path, and can be used in a microwave circuit that switches a transmission path according to reception or transmission of a radio wave (signal). It is a thing.

[0002]

2. Description of the Related Art FIG. 8 is a block diagram showing a basic structure of a conventional signal path switching microwave semiconductor switch, which includes series switches 21 (SW1) and 23 (SW3) and parallel switches 22 (SW2) and 24 ( It is composed of SW4). Such a switch is a terminal changeover switch (hereinafter, SP) that enables selection of terminals to be connected.
It is also used as a route changeover switch (hereinafter also referred to as a T / R switch) at the time of reception / transmission in a radar, a mobile communication base station / portable device, and the like.

In the case of a T / R switch, terminal 25 is an antenna feeding terminal, terminal 26 is a connection terminal to a low noise amplifier (LNA) or a frequency conversion mixer, and terminal 27 is a connection terminal to a high power amplifier. 31 to 34 are switch element control terminals.

In the figure, the control terminal 3 is set so that SW1 and SW4 are conductive and SW2 and SW3 are open.
When a predetermined DC voltage is applied to each of 1, 32, 33, and 34, the path between the terminals 25 and 26 becomes conductive, the path between the terminals 25 and 27 becomes open, and the terminal 2
The signal is transmitted only between 5 and the terminal 26.

On the other hand, SW1 and SW4 are opened, and S
When a DC voltage different from the above is applied to each control terminal so that W2 and SW3 become conductive, the path between the terminals 25 and 27 becomes conductive and the path between the terminals 25 and 26 becomes open. , The signal is transmitted only between the terminals 27 and 25.

In this way, the terminals 26 and 27 are separated from each other regardless of which path is conducting,
The connection terminal or the signal path can be switched. The semiconductor switch element is a two-terminal element that is a PIN diode that controls a current by voltage to perform a switching operation, or a three-terminal element that is a terminal that controls a resistance between two other terminals to perform a switching operation. A field effect transistor (hereinafter, also referred to as FET) is generally used. In an integrated circuit, a switch using an FET, which is relatively easy to manufacture and is capable of high-speed switching by voltage control, is the mainstream. In addition, it is small in the portable device for mobile communication.
Since lightweight and low power consumption are important items, a switch IC using an FET that does not consume power is indispensable.

FIG. 9 shows the structure of a conventional T / R switch (the same applies to SPDT switches) when an FET is used as a switch element. Corresponding parts are given the same numbers as in FIG. The drain and source electrodes of each FET are biased to ground potential and the gate terminals 31, 32, 3
Control voltages 1 and 2 different from each other, which are 0 V or less than the pinch-off voltage, are applied to 3 and 34 to change the drain-source resistance of the FET to operate as a switch.
When an FET is used, it is conductive when the gate terminal voltage is 0 V, and open when the voltage is below the pinch-off voltage.

[0008]

In the prior art as described above, when the FET is used as a switch element, the frequency becomes high due to the influence of the parasitic capacitance between the drain and source terminals in the open state. Accordingly, there is a problem that the isolation characteristic between both terminals deteriorates.

Further, there is a limit to the maximum power Pmax that can be processed when the FET is used as a switch element, and therefore, the maximum transmission power when the high output amplifier side (terminal 25-terminal 27) becomes conductive is restricted. ..

This restriction applies to SW1 and SW4 in the open state.
This is because of the high resistance, and a large voltage proportional to the 1/2 power of the transmission power is applied. The maximum power Pmax is represented by "Equation 2".

[0011]

[Equation 2]

Here, Vc, Vp, and Zo are the gate terminal control voltage, the pinch-off voltage, and the load impedance, respectively, and | Vc-Vp | is the maximum transmission signal voltage. In order to improve the maximum power Pmax, it is necessary to increase the control voltage Vc, but Vc cannot be higher than the maximum allowable voltage that can be applied between the drain and the gate or between the source and the gate. Since it is necessary to reduce the signal voltage applied to the source), the transmission power must be limited.

In a portable device or the like, it is important to reduce the size and weight by using a small battery as much as possible. Therefore, since the control voltage cannot be increased, the transmission power is further limited. become.

The present invention has been made in order to solve the above-mentioned conventional problems, and provides a switch structure having excellent isolation characteristics between both terminals, and the polarity of switch control is the same as that of the conventional structure. To provide a microwave semiconductor switch capable of maintaining a minute high frequency signal voltage applied to a switch element (FET) when opened and greatly improving processable transmission power by utilizing the fact that it is inverted. It is an object.

[0015]

According to the invention, the above object is achieved by means of the patent claims.

That is, the invention of claim 1 is a circuit in which a first semiconductor switch and an inductor (L) are connected in series,
A second semiconductor switch loaded with an inductor (L ') between both terminals and a circuit in which a capacitor (C) is connected in series are connected in parallel, and one of the first semiconductor switch and the second semiconductor switch is connected. When the switch is ON, the other is also operated so that the other switch is ON, and when the parasitic capacitance between both terminals of the first semiconductor switch and the second semiconductor switch is Cs, L '(C + Cs)
This is a microwave semiconductor switch in which the values of L, L'and C are set so that = LC and the "equation 1" described in claim 1 is satisfied at the operating frequency f.

Further, the invention of claim 2 is a circuit in which a first semiconductor switch and a capacitor (C) are connected in series, a second semiconductor switch in which a capacitor (C ') is loaded between both terminals, and an inductor (L). ) Are connected in parallel with each other, and when one of the first semiconductor switch and the second semiconductor switch is turned on, the other is also turned on so as to operate in conjunction with each other. The values of C and C'are set such that C '+ Cs = C, where Cs is the parasitic capacitance between both terminals of the first semiconductor switch and the second semiconductor switch, and the operating frequency f is set at the operating frequency f. The microwave semiconductor switch is characterized by being formed so as to satisfy "Equation 1" described in 1.

According to a third aspect of the invention, a circuit in which an inductor (L) is loaded between both terminals of a circuit in which the first semiconductor switch and the capacitor (C) are connected in series, and both terminals of the second semiconductor switch. A circuit loaded with a capacitor (C ′) is connected in series, and when one of the first semiconductor switch and the second semiconductor switch is ON, the other is ON so that the other operates. When the parasitic capacitance between both terminals of the first semiconductor switch and the second semiconductor switch is Cs, C '+
The values of C and C'are set such that Cs + CCs / (C + Cs) = C, and the operating frequency f is set at the above-mentioned value.
The microwave semiconductor switch is formed so as to satisfy "Equation 1" described in 1 above.

According to a fourth aspect of the invention, a circuit in which a capacitor (C) is loaded between both terminals of a circuit in which the first semiconductor switch and the inductor (L) are connected in series, and both terminals of the second semiconductor switch. A circuit loaded with an inductor L'is connected in series between the first semiconductor switch and the second semiconductor switch.
The parasitic capacitance between both terminals of each semiconductor switch is
When the L '· ^{[Cs + C 2 / (C-} Cs) ] = LC
The microwave semiconductor switch is configured such that the values of L, L'and C are set so as to satisfy the above condition, and the "equation 1" described in claim 1 is satisfied at the operating frequency f.

[0020]

According to the above-mentioned means, when all the switching elements are made conductive, an LC parallel (anti) resonance circuit is formed, which is opened at the resonance frequency fo regardless of the presence or absence of parasitic capacitance, and the isolation characteristic is excellent. A microwave semiconductor switch can be realized.

Further, as will be described in the embodiment section below,
When all the switching elements are opened, it can be made conductive at the resonance frequency fo. In the following description, such a switching circuit that switches the resonance / anti-resonance mode is also referred to as a resonance mode switching circuit.

In the resonance mode switching circuit of the present invention, a portion to which a large signal voltage is applied (SW1 and SW in FIGS. 8 and 9).
When used in 4), when the output signal voltage from the high-power amplifier is applied to the resonance mode switching circuit, the switch in the resonance mode switching circuit is in a conductive state, and no potential difference occurs between both terminals. Therefore, the potential difference between the drain (source) and the gate can be kept constant at approximately 0 V regardless of the transmission power.

That is, since the increase in the potential difference between the drain (source) and the gate due to the increase in the transmission power, which has occurred in the conventional case where the FET alone is used as a switch, can be eliminated, the applied signal voltage limitation is eliminated, The processable transmission power can be greatly improved.

In other words, the electric power that can be transmitted is improved by replacing the withstand voltage requirement with respect to the switch element (or circuit) with the withstand voltage characteristic. That is, for the same reason that the output of a high-power FET has a limit, the development of a FET having a high withstand voltage requires a very advanced process technology and a long development period, and further, there is a limit, but Since the current characteristic can be improved by connecting a plurality of FETs in parallel and increasing the gate width, it can be easily realized by using the conventional FET.

[0025]

1 is a diagram showing a first embodiment of a microwave semiconductor switch of the present invention. In this embodiment, switch elements 20a and 20b, inductors 50 (L) and 50 '(L'), and a capacitor 60 (C) are combined as shown in the figure. Terminals 10 and 10 'represent terminals for applying a control voltage.

Switch element 20a and switch element 20b
And operate so that when one of them is on, the other is also on. If there is no parasitic capacitance between both terminals of the switch element and the switch element operates ideally, the inductor 50 (L) and the capacitor 60 (C) resonate in parallel (anti) when both switch elements are conducting. , 100-101 between both terminals of this switch is open. Further, when both switch elements are open, the inductor 50 '(L') and the capacitor 60 (C) resonate in series, and the voltage between both terminals of this switch is 10
0-101 becomes conductive.

Here, when a parasitic capacitance of Cs exists between both terminals of the switch element, the series resonance frequency fo [s] becomes as shown in "Equation 3" and the parallel resonance frequency fo [p] becomes "Equation 4". become that way.

[0028]

[Equation 3]

[0029]

[Equation 4]

"Equation 3" is when the switch element is off, and the terminals 100 to 101 in FIG. 1 are in a conductive state. Further, "Equation 4" is when the switch element is on, and the terminals 100 to 101 in FIG. 1 are in an open state.

Therefore, by setting the values of L and L'to satisfy L '(C + Cs) = LC, conduction / open switching can be performed at the same frequency, regardless of the presence or absence of the parasitic capacitance of the switch element. High isolation can be realized in the microwave region. Moreover, the polarity of control is reversed with respect to the switch using the conventional FET or the like. This feature is very effective in improving the power resistance of the T / R switch according to the fifth embodiment described later. This also applies to the second and third embodiments.

FIG. 2 is a diagram showing a second embodiment of the microwave semiconductor switch of the present invention. In this embodiment, the switch elements 20a and 20b, the inductor 50 (L), and the capacitors 60 (C) and 60 '(C') are combined as shown in the figure. Terminals 10 and 10 'are terminals for applying a control voltage.

Assuming that there is no parasitic capacitance between both terminals of the switch element and that the switch element operates ideally, the inductor 50 (L) and the capacitor 60 (C) are connected in parallel (reversed) when both switch elements are conducting. ) It resonates, and 100-101 between both terminals of this switch becomes open. Also, when both switch elements are open, the inductor 50 (L) and the capacitor 60 'are
(C ') resonates in series, and there is 100 between both terminals of this switch.
-101 becomes conductive.

Here, the series resonance frequency fo [s] when there is a parasitic capacitance Cs at both ends of the switch element is as shown in "Equation 5", and the parallel resonance frequency fo [p] is as shown in "Equation 4". It becomes as shown in ".

[0035]

[Equation 5]

Therefore, by setting the values of C and C'to satisfy C '+ Cs = C, conduction / open switching can be performed at the same frequency, and the micro element can be used regardless of the presence or absence of the parasitic capacitance of the switch element. High isolation can be achieved in the wave region.

FIG. 3 is a diagram showing a third embodiment of the microwave switch of the present invention. In this embodiment, the switch element 2
0a and 20b, an inductor 50 (L), and capacitors 60 (C) and 60 '(C') are combined as shown in the figure. Terminals 10 and 10 'are terminals for applying a control voltage.

Assuming that there is no parasitic capacitance between both terminals of the switch element and that the switch element operates ideally, the inductor 50 (L) and the capacitor 60 (C) are connected in parallel (reversed) when both switch elements are conducting. ) It resonates, and 100-101 between both terminals of this switch becomes open. Also, when both switch elements are open, the inductor 50 (L) and the capacitor 60 'are
(C ') resonates in series, and there is 100 between both terminals of this switch.
-101 becomes conductive.

When a parasitic capacitance of Cs exists at both ends of the switch element, the series resonance frequency fo [s] becomes as shown in "Equation 6", and the parallel resonance frequency fo [p] becomes "Equation 4". It becomes as shown in ".

[0040]

[Equation 6]

Therefore, C '+ Cs + CCs / (C +
By setting the values of C and C'to satisfy Cs) = C, conduction / open switching can be performed at the same frequency, and high isolation is achieved in the microwave region regardless of the parasitic capacitance of the switch element. Can be realized.

Similar to the relationship between the first embodiment and the second embodiment, the same effect can be obtained in the third embodiment in which the inductor and the capacitor are replaced. Figure 4
It is a figure which shows the structure of the SPDT switch which carries out the terminal switching which combined the switch (it is shown as the resonance mode switching circuits 30a and 30b in the figure) of either of the above, Comprising: The 1st terminal 25 and the 2nd terminal. 26 and the first terminal 25 and the third terminal 27 are connected in series respectively.

Since the isolation characteristic of each switch is not deteriorated by the influence of the parasitic capacitance of the switch element, a good terminal switching characteristic can be realized in the microwave band near the resonance frequency. The SPDT switch is not limited to this embodiment, but the switch can be combined in series / parallel to further improve the isolation characteristic.

FIG. 5 is a diagram showing a basic structure of a T / R switch in which any one of the above resonance mode switching circuits is combined. Although the resonance mode switching circuit of the first embodiment is used here, the same applies to the resonance mode switching circuits of the second and third embodiments.

In the figure, the T / R switch of the present invention is
Inductors 51, 52 (L ₁ ) and capacitor 61 (C ₁ )
And a resonance mode switching circuit 1 (SW1) configured by combining the switch elements 1a and 1b, an inductor 54,
55 (L ₂ ), the capacitor 56 (C ₂ ) and the switching elements 4a and 4b are combined to form a resonance mode switching circuit 4 (SW4), and switching elements 2 (SW2) and 3 (S
W3) and. SW1 and SW3 are connected in series to the paths 25-26 and 25-27, respectively. SW2 and SW4 are route 25-26 and route 2 respectively.
It is connected in parallel between 5-27 and the ground.

Here, 11, 11 ', 12, 13, 1
Reference numerals 4 and 14 'denote ON / OFF control terminals of the respective switch elements, and 11 and 11' and 14 and 1 when 1a and 1b and 4a and 4b are the same type of switch elements, respectively.
The same control voltage is applied to 4 '. The operation will be described below assuming that each switch element has no parasitic capacitance.

First, the resonance mode switching function of SW1 and SW4 will be described. In SW1, when a voltage is applied to control voltages 11 and 11 'so that 1a and 1b become conductive, both ends of inductor 52 are short-circuited and inductor 51 and capacitor 61 are electrically connected at both ends. (L ₁ ) and capacitor 61
A parallel circuit with (C ₁ ) is connected in series to paths 25-26.

At this time, the paths 25-26 are opened at the resonance frequency of the L ₁ C ₁ parallel circuit and its vicinity. Also,
When a voltage is applied to the control voltages 11 and 11 'so that 1a and 1b are opened, the connection between the inductor 51 and the capacitor 61 and the short circuit between both ends of the inductor 52 are released, and the inductor 52 (L ₁ ) and the capacitor 61 (C ₁ )
A series circuit of and is connected in series to paths 25-26.

At this time, the paths 25-26 can become conductive at and near the resonance frequency of the L ₁ C ₁ series circuit. Here, the frequencies of the series resonance and the parallel resonance are the same, and they operate as a switch for the signals of the same frequency shown in "Equation 7".

[0050]

[Equation 7]

In SW4, when a voltage is applied to control voltages 14 and 14 'so that 4a and 4b become conductive, both ends of inductor 55 are short-circuited and inductor 5
4 and the capacitor 62 are electrically connected at both ends,
A parallel circuit of inductor 54 (L ₂ ) and capacitor 62 (C ₂ ) is connected in parallel between paths 25-27 and ground.

At this time, SW4 has a high impedance at and near the resonance frequency of the L ₂ C ₂ parallel circuit, and S4
When W3 is conductive, the path 25-27 is conductive. Also, 4
Control voltages 14 and 1 so that a and 4b are opened.
When a voltage is applied to the 4 ', short of both ends of the connection and the inductor 55 of the inductor 54 and the capacitor 62 is released, the inductor 55 and (L ₂₎ a series circuit of a capacitor 62 (C ₂₎ is a path 25-27 ground And are connected in parallel.

At this time, the paths 25-26 are short-circuited to the ground potential at and near the resonance frequency of the L ₂ C ₂ series circuit. Here, the frequencies of the series resonance and the parallel resonance are the same, and they operate as a switch for the signals of the same frequency shown in "Equation 8".

[0054]

[Equation 8]

Next, the operation when the values of L ₁ , L ₂ , C ₁ and C ₂ are set so that the resonance frequencies of SW1 and SW4 are the same in FIG. 5 will be described. (1) A voltage is applied to the control terminals 11, 11 ', 12 so that the switch elements 1a, 1b, 2 are opened, and the control terminals 14, 14' are also opened so that the switch elements 4a, 4b, 3 are also opened. , 13 is turned on. SW2 is opened. SW3 is opened. Since SW4 is turned on, the route 25-26 is conducted and the route 25-27 is conducted.
Is open.

Therefore, the input signal from the terminal 25 is transmitted to the terminal 26 (or the input signal from the terminal 26 is transmitted to the terminal 25) and is not transmitted to the terminal 27. (2) A voltage is applied to the control terminals 11, 11 ', 12 so that the switch elements 1a, 1b, 2 become conductive, and control terminals 14, 14' so that the switch elements 4a, 4b, 3 also become conductive. , SW13 is open. SW2 is open. SW3 is open. Therefore, the path 25-26 is opened and the path 25-26 is opened.
27 becomes conductive. Therefore, the input signal from the terminal 25 is transmitted to the terminal 27 (or the input signal from the terminal 27 is transmitted to the terminal 25) and is not transmitted to the terminal 26.

Therefore, it operates as a T / R switch. Here, the terminal 25 is an antenna terminal for both transmission and reception, the terminal 26 is a low noise amplification / frequency converter connection terminal, and the terminal 27.
Consider a T / R switch having a reception path 25-26 for transmitting a weak radio wave from the antenna to the low noise amplifier and a transmission path 25-27 for transmitting the output of the high power amplifier to the antenna.

Further, when the receiving path 25-26 is conductive (when the transmitting path 25-27 is open), the output of the high power amplifier is stopped or suppressed (the power consumption is reduced and the call and the waiting time are reduced). It is a well-known matter in mobile devices that it is important to extend).

As described in (1) and (2) above, when the transmission paths 25-27 are conducting, SW1 and SW4 are open, and the switch elements 1a, 1b, 4a, which constitute them, are open. All 4b are conductive. Also, S
W2 and SW3 are also conductive. Since SW1 and SW4 are connected between the transmission paths 25-27 and the ground and are open (high impedance), a higher voltage is applied to both terminals as the transmission output is larger.

However, since the switch elements 1a, 1b, 4a, 4b forming SW1 and SW4 are all conductive, no voltage is applied to these switch elements, and the potentials of both terminals are set to the magnitude of the transmission output. Regardless, it will be ground potential. Therefore, the transmission power can be greatly improved as compared with the conventional T / R switch in which the grounded switch element is opened and the transmission path is made conductive. still,
Since SW3 is conductive, there is no voltage difference between both terminals, so a current that is inversely proportional to the 1/2 power of the load impedance flows. Also, SW2 is conducting, but since the signal voltage is applied through SW1 having high impedance,
No current flows.

If the receiving paths 25-26 are conducting,
SW1 and SW4 are conductive, and all the switch elements 1a, 1b, 4a, 4b constituting them are open.
Also, SW2 and SW3 are open. Here, since the received signal is weak, the voltage and current are sufficiently within the permissible range in any switch element. Furthermore, the high-power amplifier is in the output stop or output suppression state.

Therefore, SW4 serving as a path for the signal current
In, the voltage applied to both terminals of the switch element 4b connected in parallel with the inductor 55 can be made very small. As described above, by connecting the resonance mode switching circuit in series to the reception path and in parallel between the transmission path and the ground, the maximum processing power can be greatly improved as compared with the conventional case.

FIG. 6 shows the switch elements 1a, 1b, 2, 3, 4a, 4b of the embodiment shown in FIG. 1 replaced with FETs. Corresponding parts have the same numbers and symbols as in FIG. The control terminal is connected to the gate of each FET.

The drain-source resistance of the FET is several ohms or less when the gate potential is 0 V when these electrodes are biased to the same potential (ground potential in the figure), and the gate potential is the pinch-off voltage Vp (< When it is 0) or less, it becomes several tens of kilo-ohms to several mega-ohms, and a high resistance ratio can be realized by using the FET as a switch element.

By utilizing this switching characteristic, a T / R switch based on the operation principle described with reference to FIG. 5 can be realized. Here, when the transmission paths 25-27 are conductive, that is, when a large voltage is applied to SW1 and SW4,
Since the FETs 4a and 4b are conductive, the drain and the source are biased to the ground potential regardless of the transmission power. Therefore, the maximum transmission power can be significantly improved.

The maximum transmission power is the inductor L ₁ (5
1) and limited by the high frequency current flowing in L ₂ (54). However, the FE having a gate width commensurate with the high frequency current
The maximum transmission power can be increased by adopting T for 1a and 1b. Where the maximum transmission power is Pm
Letting ax be the maximum high-frequency current be Imax and the resonance frequency be fo, Imax is given by "Equation 9".

[0067]

[Equation 9]

If an FET with a gate width of about 1 mm is used, a current of about 200 mA can flow, so
When πfoL is about 40, it can withstand a transmission power of 30 W or more. FIG. 7 is an example in which each control terminal is integrated into one in the same T / R switch as in FIG. Some numbers are omitted in the figure. As described with reference to FIG. 1, the control voltage for each FET is the same when the transmission or reception path is in the conductive state, so that each control terminal can be connected to a common terminal. This is indicated by the broken line in the figure.

[0069]

As described above, the present invention is a switch that switches to a parallel (anti) resonance / series resonance state by switching a switching element to a conducting / opening state, and therefore, in a high frequency region such as microwaves. ,
It has good isolation characteristics that are not affected by the parasitic capacitance of the switch element. In addition, since the high frequency signal voltage applied to the switch element is kept minute when opened, the transmittable power of the T / R switch can be greatly improved.

Further, the present invention can be constructed not only by FET but also by using various semiconductor switch elements such as PIN diodes, and the transmission power is increased as compared with the conventional T / R switch by each semiconductor switch. can do. Further, since the system of control terminals can be made common, there is an advantage that the control circuit can be simplified.

[Brief description of drawings]

FIG. 1 is a diagram showing a configuration of a first exemplary embodiment of the present invention.

FIG. 2 is a diagram showing a configuration of a second exemplary embodiment of the present invention.

FIG. 3 is a diagram showing a configuration of a third exemplary embodiment of the present invention.

FIG. 4 is a diagram showing a configuration of an embodiment of an SPDT switch to which the microwave semiconductor switch of the present invention is applied.

FIG. 5 is a diagram showing a configuration of an embodiment of a T / R switch to which the microwave semiconductor switch of the present invention is applied.

FIG. 6 is a circuit diagram in the case where the switch element is an FET in the configuration of the embodiment of FIG.

7 is a diagram showing an example in which the control terminals of the switch elements are made common in the configuration of FIG.

FIG. 8 is a diagram showing a basic configuration of a conventional microwave semiconductor switch.

FIG. 9 is a diagram showing an example of a conventional microwave semiconductor switch.

[Explanation of symbols]

1, 4 Co-vibration mode switching circuit 1a, 1b, 2, 3, 4a, 4b, 20a, 20b
Switch elements 10, 10 ', 11, 11', 12, 13, 14, 1
4'Switch element control terminal 21-24 Switch element 31-34 Control terminal of the above switch element 25 Microwave semiconductor switch terminal (antenna connection terminal) 26 Microwave semiconductor switch terminal (low noise amplifier / frequency converter connection terminal) ) 27 microwave semiconductor switch terminals (high-power amplifier connection terminals) 30a, 30b resonance mode switching circuit 50 inductor (L) 50 'inductor (L') 51 inductor (L ₁ ) 54, 55 inductor (L ₂ ) 60 capacitor (C) 60 'capacitor (C') 61 capacitor (C ₁ ) 62 capacitor (C ₂ ) 100, 101 terminals of microwave semiconductor switch

Claims (4)

[Claims] 1. A circuit in which a first semiconductor switch and an inductor (L) are connected in series, and a circuit in which a second semiconductor switch in which an inductor (L ') is loaded between both terminals and a capacitor (C) are connected in series. Are connected in parallel, and when one of the first semiconductor switch and the second semiconductor switch is turned on, the other is also turned on so as to operate in an interlocking manner. When the parasitic capacitance between both terminals of each of the two semiconductor switches is Cs, L '(C +
A microwave semiconductor switch characterized in that the values of L, L'and C are set so that Cs) = LC, and "Equation 1" is satisfied at the operating frequency f. [Equation 1] 2. A circuit in which a first semiconductor switch and a capacitor (C) are connected in series, and a circuit in which a second semiconductor switch in which a capacitor (C ′) is loaded between both terminals and an inductor (L) are connected in series. Are connected in parallel, and when one of the first semiconductor switch and the second semiconductor switch is turned on, the other is also turned on so as to operate in an interlocking manner. When the parasitic capacitance between both terminals of each of the two semiconductor switches is Cs, C '+ Cs
A microwave semiconductor switch characterized in that the values of C and C'are set such that = C, and that the operating frequency f satisfies "Equation 1" according to claim 1. 3. A circuit in which an inductor (L) is loaded between both terminals of a circuit in which a first semiconductor switch and a capacitor (C) are connected in series, and a capacitor (C ′) between both terminals of a second semiconductor switch.
And a circuit in which the first semiconductor switch and the second semiconductor switch are turned on, the two circuits are connected in series, and when one of the first semiconductor switch and the second semiconductor switch is turned on, the other is turned on. C '+ Cs, where Cs is the parasitic capacitance between both terminals of the semiconductor switch and the second semiconductor switch.
C and C'so that + CCs / (C + Cs) = C
The microwave semiconductor switch is characterized in that the value is set to satisfy the "Equation 1" described in claim 1 at the operating frequency f. 4. A circuit in which a capacitor (C) is loaded between both terminals of a circuit in which a first semiconductor switch and an inductor (L) are connected in series, and an inductor L ′ is loaded between both terminals of a second semiconductor switch. When the parasitic capacitance between the two terminals of the first semiconductor switch and the second semiconductor switch is Cs, L '. [C
The values of L, L ′ and C are set so that s + C ² / (C−Cs)] = LC, and the operation frequency f is set to satisfy “Equation 1” described in claim 1. And microwave semiconductor switch.