On / off switching circuit

Abstract

To provide an ON / OFF switching circuit of a simple configuration which does not require a capacitor for DC cut.SOLUTION: The on / off switching circuit 100 includes a first circuit 110 and a second circuit 120. The first circuit 110 includes a pair of a first diode 111 and a second diode 112 whose cathode terminals or anode terminals are connected to each other, and is configured to be capable of outputting AC power input to one end 110in from the other end 110out. The second circuit 120 applies a forward bias voltage or a reverse bias voltage to each of the first diode 111 and the second diode 112 to turn on and off the first diode 111 and the second diode 112, and applies the same forward bias voltage or reverse bias voltage to each of the first diode 111 and the second diode 112 to turn on and off the first diode 111 and the second diode 112 in synchronization.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to an on-off switching circuit. [Background technology]

[0002] BACKGROUND ART Conventionally, for example, in plasma processing apparatuses used for etching or the like in manufacturing semiconductor devices, RF pulses obtained by pulse-modulating the output of an RF power supply (RF: Radio Frequency) may be used.

[0003] Patent Document 1 listed below discloses a technology for controlling the level of an output signal in a switch circuit that includes diodes inserted in series in each signal line and a control circuit that applies a forward bias voltage or a reverse bias voltage to each diode to turn each diode on and off, by variably controlling the forward current that flows through the diode when the diode is on. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 06-085643 Summary of the Invention [Problem to be solved by the invention]

[0005] However, in the above-mentioned conventional technology, a DC blocking capacitor is generally required between the input / output terminal and the diode inserted in the signal line connected to the input / output terminal of the switch circuit, which poses a problem of increasing the number of components in the switch circuit.

[0006] The present invention provides an on / off switching circuit with a simple configuration that does not require a DC blocking capacitor. [Means for solving the problem]

[0007] One aspect of the present invention is a first circuit having a pair of diodes whose cathode terminals or anode terminals are connected to each other and capable of outputting AC power input to one end from the other end; a second circuit that applies a forward bias voltage or a reverse bias voltage to each of the pair of diodes to turn the pair of diodes on and off; Equipped with the second circuit applies the same forward bias voltage or the same reverse bias voltage to each of the pair of diodes, thereby synchronously turning the pair of diodes on and off; It is an on / off switching circuit. [Effects of the Invention]

[0008] According to the present invention, it is possible to provide an on / off switching circuit with a simple configuration that does not require a DC blocking capacitor. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 1 is a diagram showing an example of the configuration of an on / off switching circuit 100 according to this embodiment. [Figure 2] FIG. 2 is a diagram showing a first example of the effect of the on / off switching circuit 100. In FIG. [Figure 3] FIG. 3 is a diagram showing a second example of the effect achieved by the on / off switching circuit 100. In FIG. DETAILED DESCRIPTION OF THE INVENTION

[0010] An embodiment of an on / off switching circuit of the present invention will be described in detail below with reference to the drawings. The drawings should be viewed in the direction of the reference symbols. Note that not all elements described in the following embodiment are necessarily essential to the present invention. Furthermore, two or more of the elements described in the following embodiment may be arbitrarily combined. Hereinafter, identical or similar elements will be assigned identical or similar reference symbols, and their description may be omitted or simplified.

[0011] (1. Configuration of the on / off switching circuit) First, a description will be given of an example of the configuration of an on / off switching circuit 100 according to one embodiment of the present invention. Fig. 1 is a diagram showing an example of the configuration of an on / off switching circuit 100 according to this embodiment.

[0012] The on / off switching circuit 100 shown in FIG. 1 is a circuit that is provided, for example, between an RF power source (RF: Radio Frequency) not shown and a load, and is capable of switching between "on" in which RF power output from the RF power source is output to the load, and "off" in which RF power is not output to the load.

[0013] Here, RF power is an example of AC power. The load may be a capacitive load such as plasma generated between a cathode electrode and a counter electrode that are disposed opposite each other at a predetermined distance in a chamber of a plasma processing apparatus. A matching box for impedance matching may be provided between the RF power supply and the on-off switching circuit 100, or between the on-off switching circuit 100 and the load.

[0014] As shown in FIG. 1, the on / off switching circuit 100 includes a first circuit 110, a second circuit 120, a filter circuit 130, and a control unit 140, for example.

[0015] The first circuit 110 has a first diode 111 and a second diode 112 connected in series, and is configured to be able to output RF power input to one end 110in from the other end 110out. The first diode 111 and the second diode 112 are an example of a pair of diodes. The one end 110in is electrically connected (hereinafter also simply referred to as "connected") to, for example, the RF power source or matching box described above. The other end 110out is connected to, for example, the load or matching box described above.

[0016] The first diode 111 is a diode that is provided on the one end 110in side of the first diode 111 and the second diode 112. As an example, in this embodiment, the first diode 111 is a PIN diode, and the anode terminal of the first diode 111 is connected to the one end 110in that is the input side of the first circuit 110.

[0017] The second diode 112 is a diode that is provided on the other end 110out side of the first diode 111 and the second diode 112. As an example, in this embodiment, the second diode 112 is a PIN diode, and the anode terminal of the second diode 112 is connected to the other end 110out, which is the output side of the first circuit 110.

[0018] In this embodiment, the first diode 111 and the second diode 112 function as switches for turning on and off the RF power output from the first circuit 110. By configuring the first diode 111 and the second diode 112 as PIN diodes, the withstand voltage of the first diode 111 and the second diode 112 can be easily ensured compared to when these diodes are configured as diodes other than PIN diodes, and therefore it becomes possible to adapt to RF power having a larger RF voltage.

[0019] 1, the cathode terminals of the first diode 111 and the second diode 112 are connected to each other. A connection point P1 between the cathode terminals of the first diode 111 and the second diode 112 is connected to the reference potential line Lref of the second circuit 120 via a fifth inductor 135 (described later). The reference potential line Lref is a floating power line that is insulated from the ground and has a reference potential Vref. Therefore, the reference potential Vref is applied to the connection point P1. In other words, the potentials of the cathode terminals of the first diode 111 and the second diode 112 can be set as the reference potential Vref.

[0020] The second circuit 120 is a circuit that applies a forward bias voltage or a reverse bias voltage to each of the first diode 111 and the second diode 112 to turn on and off the first diode 111 and the second diode 112. The second circuit 120 applies the forward bias voltage or the reverse bias voltage to the first diode 111 and the second diode 112, for example, under the control of the control unit 140, which will be described later.

[0021] Specifically, the second circuit 120 has a first bias voltage circuit section 121 that applies a forward bias voltage or a reverse bias voltage to the first diode 111, and a second bias voltage circuit section 122 that applies a forward bias voltage or a reverse bias voltage to the second diode 112.

[0022] The forward bias voltage applied to the first diode 111 by the first bias voltage circuit unit 121 and the forward bias voltage applied to the second diode 112 by the second bias voltage circuit unit 122 are greater than 0 [V] and have the same voltage value. An example of these bias voltages is 5 [V].

[0023] The reverse bias voltage applied to the first diode 111 by the first bias voltage circuit unit 121 and the reverse bias voltage applied to the second diode 112 by the second bias voltage circuit unit 122 are smaller than 0 [V] and have the same voltage value. An example of these bias voltages is −800 [V].

[0024] The first bias voltage circuit section 121 has a first high-side switch 121a and a first low-side switch 121b. The first bias voltage circuit section 121 also has a high-potential side input terminal 121c to which a DC voltage having a positive bias voltage (for example, 5 [V]) greater than 0 [V] is input from a DC power supply (not shown), a low-potential side input terminal 121d to which a DC voltage having a negative bias voltage (for example, −800 [V]) less than 0 [V] is input from a DC power supply (not shown), capacitors 121e and 121f, and a resistor 121g.

[0025] The first high-side switch 121a and the first low-side switch 121b are connected in series between the high-potential side input terminal 121c and the low-potential side input terminal 121d of the first bias voltage circuit section 121, with the first high-side switch 121a on the high-potential side input terminal 121c side and the first low-side switch 121b on the low-potential side input terminal 121d side. A resistor 121g is provided between the first high-side switch 121a and the first low-side switch 121b.

[0026] Furthermore, the first high-side switch 121a and the first low-side switch 121b are each connected to the control unit 140 and operate under the control of the control unit 140. In other words, under the control of the control unit 140, the first bias voltage circuit unit 121 (i.e., the second circuit 120) applies a positive bias voltage input from a DC power supply to the first diode 111 as a forward bias voltage, and applies a negative bias voltage input from the DC power supply to the first diode 111 as a reverse bias voltage.

[0027] The first high-side switch 121a and the first low-side switch 121b are each realized by, for example, an NMOS transistor. In this case, the control unit 140 is connected to the gate terminals of the first high-side switch 121a and the first low-side switch 121b. As a result, the control unit 140 can turn the first high-side switch 121a and the first low-side switch 121b on (i.e., conductive state) or off (i.e., non-conductive state) by controlling the gate voltages applied to the gate terminals of the first high-side switch 121a and the first low-side switch 121b.

[0028] The first high-side switch 121a and the first low-side switch 121b may each be configured by a plurality of switching elements (for example, NMOS transistors) connected in series.

[0029] The capacitor 121e is provided in parallel with the first high-side switch 121a and functions as a bypass capacitor that stabilizes the DC voltage (e.g., positive bias voltage) input to the first bias voltage circuit unit 121 and removes high-frequency noise. Similarly, the capacitor 121f is provided in parallel with the first low-side switch 121b and functions as a bypass capacitor that stabilizes the DC voltage (e.g., negative bias voltage) input to the first bias voltage circuit unit 121 and removes high-frequency noise. The resistor 121g functions as a damping resistor that suppresses voltage overshoot when the first diode 111 transitions from off to on.

[0030] The second bias voltage circuit section 122 has a second high-side switch 122a and a second low-side switch 122b. The second bias voltage circuit section 122 also has a high-potential side input terminal 122c to which a DC voltage having a positive bias voltage (e.g., 5V) greater than 0V is input from a DC power supply (not shown), a low-potential side input terminal 122d to which a DC voltage having a negative bias voltage (e.g., −800V) less than 0V is input from a DC power supply (not shown), capacitors 122e and 122f, and a resistor 122g.

[0031] The second high-side switch 122a and the second low-side switch 122b are connected in series between the high-potential side input terminal 122c and the low-potential side input terminal 122d of the second bias voltage circuit section 122, with the second high-side switch 122a on the high-potential side input terminal 122c side and the second low-side switch 122b on the low-potential side input terminal 122d side. A resistor 122g is provided between the second high-side switch 122a and the second low-side switch 122b.

[0032] Furthermore, the second high-side switch 122a and the second low-side switch 122b are each connected to the control unit 140 and operate under the control of the control unit 140. In other words, the second bias voltage circuit unit 122 (i.e., the second circuit 120) applies a positive bias voltage input from a DC power supply to the second diode 112 as a forward bias voltage, and applies a negative bias voltage input from the DC power supply to the second diode 112 as a reverse bias voltage.

[0033] The second high-side switch 122a and the second low-side switch 122b are each realized by, for example, an NMOS transistor. In this case, the control unit 140 is connected to the gate terminals of the second high-side switch 122a and the second low-side switch 122b. This allows the control unit 140 to turn on and off the second high-side switch 122a and the second low-side switch 122b by controlling the gate voltages applied to the gate terminals of the second high-side switch 122a and the second low-side switch 122b.

[0034] The second high-side switch 122a and the second low-side switch 122b may each be configured by a plurality of switching elements (for example, NMOS transistors) connected in series.

[0035] The capacitor 122e is provided in parallel with the second high-side switch 122a and functions as a bypass capacitor that stabilizes the DC voltage (e.g., positive bias voltage) input to the second bias voltage circuit unit 122 and removes high-frequency noise. Similarly, the capacitor 122f is provided in parallel with the second low-side switch 122b and functions as a bypass capacitor that stabilizes the DC voltage (e.g., negative bias voltage) input to the second bias voltage circuit unit 122 and removes high-frequency noise. The resistor 122g functions as a damping resistor that suppresses voltage overshoot when the second diode 112 transitions from off to on.

[0036] The filter circuit 130 is provided between the first circuit 110 and the second circuit 120, and is a circuit that suppresses RF power input to the first circuit 110 from flowing into the second circuit 120. The second circuit 120 may have stray capacitance, and in order to suppress the flow of RF power into the stray capacitance of the second circuit 120, the filter circuit 130 is preferably configured as described below.

[0037] The filter circuit 130 includes a first filter section 131 having a first inductor 131a and a first capacitor 131b connected in series, and a second filter section 132 having a second inductor 132a and a second capacitor 132b connected in series. For example, the impedances of the first inductor 131a and the second inductor 132a are set equal to each other in order to balance the voltages applied to the first diode 111 and the second diode 112, respectively.

[0038] It is preferable that the impedance of each of the first inductor 131a and the second inductor 132a be relatively large in order to prevent RF power from leaking to the other end 110out (i.e., the output side) through the inductors. On the other hand, it is preferable that the impedance of each of the first inductor 131a and the second inductor 132a be smaller than the impedance of each of the third inductor 133, the fourth inductor 134, and the fifth inductor 135.

[0039] The filter circuit 130 also includes a third inductor 133, a fourth inductor 134, and a fifth inductor 135, each of which has a higher impedance than the first inductor 131a and the second inductor 132a. For example, the impedances of the third inductor 133, the fourth inductor 134, and the fifth inductor 135 are assumed to be equal to each other.

[0040] 1, one end of the first filter section 131 on the first inductor 131a side is connected between one end 110in of the first circuit 110 and the first diode 111. More specifically, in this embodiment, one end of the first filter section 131 on the first inductor 131a side is connected to the anode terminal of the first diode 111 connected to one end 110in.

[0041] 1, the other end of the first filter section 131 on the first capacitor 131b side is connected to the reference potential line Lref via a fifth inductor 135. More specifically, in this embodiment, the other end of the first filter section 131 on the first capacitor 131b side is connected between the fifth inductor 135 and a connection point P1 between the cathode terminals of the first diode 111 and the second diode 112.

[0042] A connection point P4 between the first inductor 131a and the first capacitor 131b in the first filter section 131 is connected to the first bias voltage circuit section 121 via the third inductor 133. More specifically, in this embodiment, the connection point P4 is connected via the third inductor 133 to a connection point P5 provided between the first high-side switch 121a and the first low-side switch 121b in the first bias voltage circuit section 121 (more specifically, between the resistor 121g and the first low-side switch 121b).

[0043] 1, one end of the second filter section 132 on the second inductor 132a side is connected between the other end 110out of the first circuit 110 and the second diode 112. More specifically, in this embodiment, one end of the second filter section 132 on the second inductor 132a side is connected to the anode terminal of the second diode 112 connected to the other end 110out.

[0044] 1, the other end of the second filter section 132 on the second capacitor 132b side is connected to the reference potential line Lref via the fifth inductor 135. More specifically, in this embodiment, the other end of the second filter section 132 on the second capacitor 132b side is connected between the fifth inductor 135 and a connection point P1 between the cathode terminals of the first diode 111 and the second diode 112, similar to the other end of the first filter section 131 on the first capacitor 131b side.

[0045] A connection point P7 between the second inductor 132a and the second capacitor 132b in the second filter section 132 is connected to the second bias voltage circuit section 122 via the fourth inductor 134. More specifically, in this embodiment, the connection point P7 is connected via the fourth inductor 134 to a connection point P8 provided between the second high-side switch 122a and the second low-side switch 122b in the second bias voltage circuit section 122 (more specifically, between the resistor 122g and the second low-side switch 122b).

[0046] 1 includes the third inductor 133, the fourth inductor 134, and the fifth inductor 135, so that at least one inductor exists on each path through which current can flow from the first circuit 110 to the second circuit 120. Therefore, each path can be maintained at a high impedance compared to when no inductor exists on each path. This makes it possible to prevent RF power from the first circuit 110 from flowing into the second circuit 120.

[0047] However, the configuration of the filter circuit 130 is not limited to the example described here. For example, if the wiring between the connection point P4 and the connection point P5 shown in FIG. 1 has sufficient impedance (more specifically, impedance greater than that of the first inductor 131a), it is not necessary to separately provide the third inductor 133 as a component.

[0048] Similarly, if the wiring between connection point P7 and connection point P8 has sufficient impedance, there is no need to provide a separate fourth inductor 134 as a component, and if the wiring between connection point P3 and the reference potential line Lref has sufficient impedance, there is no need to provide a separate fifth inductor 135 as a component.

[0049] In other words, only the first filter section 131 and the second filter section 132 may be provided as the filter circuit 130. In this way, the configuration of the filter circuit 130 can be simplified, and the first filter section 131 and the second filter section 132, which are LC filters that can be easily and simply configured, can suppress the RF power input to the first circuit 110 from flowing into the second circuit 120.

[0050] Furthermore, if the wiring between the connection points P2 and P4 has sufficient impedance, the first inductor 131a does not need to be provided separately as a component, and if the wiring between the connection points P6 and P7 has sufficient impedance, the second inductor 132a does not need to be provided separately as a component. Furthermore, the filter circuit 130 itself may be omitted as appropriate.

[0051] The control unit 140 controls the second circuit 120 to turn on and off the first diode 111 and the second diode 112. For example, the control unit 140 is realized by a microcomputer or the like configured to include a CPU (Central Processing Unit), a memory, an I / F (Interface), and the like.

[0052] (2. Operation of the on / off switching circuit) Next, an example of the operation of the on / off switching circuit 100 of this embodiment will be described. In the on / off switching circuit 100, the control unit 140 synchronously turns on and off the first diode 111 and the second diode 112. In other words, when the control unit 140 turns on the first diode 111 and the second diode 112, it turns them on simultaneously, and when the control unit 140 turns off the first diode 111 and the second diode 112, it turns them off simultaneously.

[0053] The control unit 140 may turn on and off the first diode 111 and the second diode 112 at a predetermined cycle, or may turn on and off the first diode 111 and the second diode 112 based on a control signal received from an external device (not shown) or the like. In other words, the timing at which the control unit 140 turns on and off the first diode 111 and the second diode 112 is not particularly limited.

[0054] When turning on the first diode 111 and the second diode 112, the control unit 140 controls the second circuit 120 so that a forward bias voltage is applied to each of the first diode 111 and the second diode 112. Specifically, the control unit 140 turns on the first high-side switch 121a of the first bias voltage circuit unit 121 and turns off the first low-side switch 121b, thereby applying a forward bias voltage to the first diode 111. Furthermore, the control unit 140 turns on the second high-side switch 122a of the second bias voltage circuit unit 122 and turns off the second low-side switch 122b, thereby applying a forward bias voltage to the second diode 112.

[0055] On the other hand, when turning off the first diode 111 and the second diode 112, the control unit 140 controls the second circuit 120 so that a reverse bias voltage is applied to each of the first diode 111 and the second diode 112. Specifically, at this time, the control unit 140 turns off the first high-side switch 121a of the first bias voltage circuit unit 121 and turns on the first low-side switch 121b, so that a reverse bias voltage is applied to the first diode 111. At this time, the control unit 140 also turns off the second high-side switch 122a of the second bias voltage circuit unit 122 and turns on the second low-side switch 122b, so that a reverse bias voltage is applied to the second diode 112.

[0056] (3. Effect of the on / off switching circuit) Next, an example of the effect of the on / off switching circuit 100 of this embodiment will be described. FIG. 2 is a diagram showing a first example of the effect of the on / off switching circuit 100. In (a) of FIG. 2, the vertical axis represents the input voltage to one end 110in of the first circuit 110, and the horizontal axis represents the timing. In (b) of FIG. 2, the vertical axis represents the voltage across the first diode 111 (specifically, the voltage at the cathode terminal on the other end 110out relative to the anode terminal on the one end 110in), and the horizontal axis represents the timing. In (c) of FIG. 2, the vertical axis represents the voltage across the second diode 112 (specifically, the voltage at the anode terminal on the other end 110out relative to the cathode terminal on the one end 110in), and the horizontal axis represents the timing. In (d) of FIG. 2, the vertical axis represents the output voltage from the other end 110out of the first circuit 110, and the horizontal axis represents the timing.

[0057] The period T11 from time t10 to time t11 shown in FIG. 2 is a period during which the first diode 111 and the second diode 112 are turned off by applying a reverse bias voltage to each of the first diode 111 and the second diode 112.

[0058] During the period T11, the first diode 111 and the second diode 112 are off, and therefore can be considered equivalent to a capacitor with a very small capacitance. In other words, during the period T11, the first diode 111 and the second diode 112 each have a high impedance. This allows the impedance of the first circuit 110, more specifically, the impedance between one end 110in and the other end 110out, to be increased during the period T11.

[0059] The output voltage from the other end 110out is, for example, a voltage divided by the first circuit 110 and a load connected to the other end 110out. Therefore, by setting the first diode 111 and the second diode 112 to high impedance and increasing the impedance of the first circuit 110, the output voltage from the other end 110out can be made approximately 0 [V], as shown in (d) of Fig. 2. Therefore, it is possible to prevent RF power from being output from the other end 110out.

[0060] FIG. 3 is a diagram showing a second example of the effect of the on / off switching circuit 100. In FIG. 3(a), the vertical axis represents the input voltage to one end 110in of the first circuit 110, and the horizontal axis represents time. In FIG. 3(b), the vertical axis represents the voltage across the first diode 111 (specifically, the voltage at the cathode terminal at the other end 110out relative to the anode terminal at one end 110in), and the horizontal axis represents time. In FIG. 3(c), the vertical axis represents the voltage across the second diode 112 (specifically, the voltage at the anode terminal at the other end 110out relative to the cathode terminal at one end 110in), and the horizontal axis represents time. In FIG. 3(d), the vertical axis represents the output voltage from the other end 110out of the first circuit 110, and the horizontal axis represents time.

[0061] The period T21 from time t20 to time t21 shown in FIG. 3 is a period during which the first diode 111 and the second diode 112 are turned on by applying a forward bias voltage to each of the first diode 111 and the second diode 112.

[0062] During the period T21, the first diode 111 and the second diode 112 are on, and therefore can be regarded as equivalent resistors having a very small electrical resistance. As a result, during the period T21, the impedance of the first circuit 110, more specifically, the impedance between one end 110in and the other end 110out, can be reduced. By reducing the impedance of the first circuit 110, an output voltage corresponding to the input voltage to the one end 110in can be output from the other end 110out, as shown in (d) of FIG. 3. Therefore, RF power can be output from the other end 110out.

[0063] As described above, according to the on / off switching circuit 100 of this embodiment, it is possible to switch on and off the RF power output from the first circuit 110 by simple control such as applying a forward bias voltage or a reverse bias voltage to the first diode 111 and the second diode 112, which are a pair of diodes of the first circuit 110.

[0064] In response to this, for example, a configuration is conceivable in which an amplifier circuit is provided in the first circuit 110 and the RF power output from the first circuit 110 is switched on and off by this amplifier circuit. However, since the control of the amplifier circuit tends to be complicated, with such a configuration, it becomes difficult to switch on and off the RF power output from the first circuit 110 with simple control.

[0065] Furthermore, according to the on / off switching circuit 100 of this embodiment, an equal forward bias voltage or reverse bias voltage is applied to each of the first diode 111 and the second diode 112, which constitute a pair of diodes in the first circuit 110, to synchronously turn on and off the pair of diodes. Here, since the cathode terminals of the first diode 111 and the second diode 112 are connected to each other, whether a forward bias voltage or a reverse bias voltage is applied to each diode, the apparent voltage (i.e., potential difference) across both ends of the pair of diodes in the first circuit 110 (i.e., the anode terminal of the first diode 111 and the anode terminal of the second diode 112) is 0 [V].

[0066] Therefore, even if DC blocking capacitors are not provided across the pair of diodes in the first circuit 110 (for example, between the anode terminal and one end 110in of the first diode 111, and between the anode terminal and the other end 110out of the second diode 112), it is possible to prevent a DC voltage caused by a forward bias voltage or a reverse bias voltage of the pair of diodes from being output to the outside from one end 110in or the other end 110out of the first circuit 110. This makes it possible to provide an on / off switching circuit 100 with a simple configuration that does not require DC blocking capacitors across the pair of diodes in the first circuit 110.

[0067] Furthermore, according to the on / off switching circuit 100 of this embodiment, the switch of the first circuit 110 is configured by a pair of diodes, the first diode 111 and the second diode 112, connected in series, so that the voltage applied to each element by the RF power input to the first circuit 110 can be lowered compared to when this switch is configured by a single element. This makes it possible to adapt to RF power having a larger RF voltage without improving the withstand voltage of each element (for example, the first diode 111 and the second diode 112) that configures the switch of the first circuit 110.

[0068] In the present embodiment, the cathode terminals of the first diode 111 and the second diode 112 are connected to each other, but this is not limiting. That is, the anode terminals of the first diode 111 and the second diode 112 may be connected to each other. Even in this case, the apparent voltage across both ends of the pair of diodes in the first circuit 110 (i.e., the cathode terminal of the first diode 111 and the cathode terminal of the second diode 112) can be set to 0 [V] when a forward bias voltage and a reverse bias voltage are applied to each diode. Therefore, even if DC blocking capacitors are not provided across the pair of diodes in the first circuit 110 (for example, between the cathode terminal and one end 110in of the first diode 111 and between the cathode terminal and the other end 110out of the second diode 112), it is possible to prevent a DC voltage caused by a forward bias voltage or a reverse bias voltage of the pair of diodes from being output to the outside from the one end 110in, which is the input side of the first circuit 110, or the other end 110out, which is the output side. However, in this case, it should be noted that the second circuit 120 needs to apply a negative potential (for example, −800 [V]) as a reference potential Vref to the connection point between the anode terminals of the first diode 111 and the second diode 112, which may complicate the configuration of the second circuit 120.

[0069] In other words, according to the on / off switching circuit 100 of this embodiment, the cathode terminals of the first diode 111 and the second diode 112 are connected to each other, which makes it possible to prevent the configuration of the second circuit 120 from becoming complicated compared to when the anode terminals of the first diode 111 and the second diode 112 are connected to each other.

[0070] Furthermore, according to the on / off switching circuit 100 of this embodiment, the first diode 111 and the second diode 112 as a pair of diodes in the first circuit 110 are each configured as PIN diodes, so it is possible to easily ensure the voltage resistance of the first diode 111 and the second diode 112 compared to when these are configured as diodes other than PIN diodes.

[0071] Furthermore, according to the on / off switching circuit 100 of this embodiment, the first circuit 110 and the second circuit 120 are connected via the filter circuit 130, so that it is possible to prevent RF power input to the first circuit 110 from flowing into the second circuit 120.

[0072] Furthermore, the filter circuit 130 of the on / off switching circuit 100 of this embodiment has a first filter section 131 and a second filter section 132 which are LC filters. This makes it possible to prevent RF power input to the first circuit 110 from flowing into the second circuit 120 by the first filter section 131 and the second filter section 132 which are LC filters that can be easily and simply configured.

[0073] Furthermore, if RF power flows from the first circuit 110 to the second circuit 120, i.e., if a leakage current occurs from the first circuit 110 to the second circuit 120, the voltages applied to the first diode 111 and the second diode 112 may become unbalanced, and a large voltage may be applied to one of the diodes. If this occurs, the withstand voltage requirements of the diode to which the large voltage is applied become strict. Furthermore, the power loss (in other words, heat generation) may also be shared by one of the diodes. Therefore, if RF power flows from the first circuit 110 to the second circuit 120, it may not be possible to fully utilize the advantages obtained by configuring the switch of the first circuit 110 with a pair of diodes, the first diode 111 and the second diode 112.

[0074] In this regard, the filter circuit 130 of the on / off switching circuit 100 of this embodiment has the third inductor 133, the fourth inductor 134, and the fifth inductor 135 in addition to the first filter section 131 and the second filter section 132 described above, and therefore at least one inductor is present on each path through which a current can flow from the first circuit 110 to the second circuit 120. This makes it possible to maintain high impedance on each of these paths and to prevent RF power from the first circuit 110 from flowing into the second circuit 120. This makes it possible to prevent a large voltage from being applied unevenly to one of the first diode 111 and the second diode 112, and makes it possible to accommodate RF power with a larger RF voltage without improving the voltage resistance or heat resistance of the first diode 111 and the second diode 112.

[0075] Although the embodiments of the present invention have been described above, it goes without saying that the present invention is not limited to these examples. It is clear that a person skilled in the art can conceive of various modifications or alterations within the scope of the claims, and it is understood that these also naturally fall within the technical scope of the present invention. Furthermore, the components of the above embodiments may be combined in any manner without departing from the spirit of the invention.

[0076] This specification etc. describes at least the following matters. Note that the components etc. corresponding to those in the above-mentioned embodiment are shown in parentheses, but are not limited to these.

[0077] (1) A first circuit (first circuit 110) having a pair of diodes (first diode 111, second diode 112) whose cathode terminals or anode terminals are connected to each other, and capable of outputting AC power input to one end (one end 110in) from the other end (the other end 110out); a second circuit (second circuit 120) that applies a forward bias voltage or a reverse bias voltage to each of the pair of diodes to turn the pair of diodes on and off; Equipped with the second circuit applies the same forward bias voltage or the same reverse bias voltage to each of the pair of diodes, thereby synchronously turning the pair of diodes on and off; On / off switching circuit.

[0078] According to (1), an equal forward bias voltage or reverse bias voltage is applied to each of a pair of diodes in the first circuit, synchronously turning the pair of diodes on and off. Here, because the cathode terminals or anode terminals of the pair of diodes are connected to each other, whether a forward bias voltage or a reverse bias voltage is applied to each of the pair of diodes, the apparent voltage (potential difference) across the pair of diodes in the first circuit is 0 V. Therefore, even without providing DC blocking capacitors across the pair of diodes in the first circuit, it is possible to prevent DC voltages caused by the forward bias voltage or reverse bias voltage of the pair of diodes from being output to the outside from one end (the input side) or the other end (the output side) of the first circuit. This makes it possible to provide an on / off switching circuit with a simple configuration that does not require DC blocking capacitors across the pair of diodes in the first circuit. Furthermore, according to (1), since the switch of the first circuit is configured with a pair of diodes, the AC voltage applied to each element can be lowered compared to when this switch is configured with a single element, and it becomes possible to adapt to AC power with a larger AC voltage without improving the voltage resistance of each element.

[0079] (2) The on / off switching circuit according to (1), The cathode terminals of the pair of diodes are connected to each other, a connection point (connection point P1) between the cathode terminals is connected to a reference potential line (reference potential line Lref) of the second circuit; On / off switching circuit.

[0080] According to (2), it is possible to prevent the configuration of the second circuit from becoming complicated, compared to when the anode terminals of the pair of diodes are connected to each other.

[0081] (3) The on / off switching circuit according to (1), The pair of diodes are each a PIN diode. On / off switching circuit.

[0082] According to (3), it is possible to easily ensure the withstand voltage of each diode, compared to when each of the pair of diodes is configured with a diode other than a PIN diode.

[0083] (4) An on / off switching circuit according to any one of (1) to (3), The first circuit and the second circuit are connected via a filter circuit (filter circuit 130) that prevents the AC power input to the first circuit from flowing into the second circuit. On / off switching circuit.

[0084] According to (4), it is possible to prevent AC power input to the first circuit from flowing into the second circuit.

[0085] (5) The on / off switching circuit according to (4), The pair of diodes is configured by connecting cathode terminals of a first diode (first diode 111) at one end of the first circuit and a second diode (second diode 112) at the other end of the first circuit, a connection point (connection point P1) between the cathode terminals is connected to a reference potential line (reference potential line Lref) of the second circuit; The second circuit is a first bias voltage circuit unit (first bias voltage circuit unit 121) that applies the forward bias voltage or the reverse bias voltage to the first diode; a second bias voltage circuit unit (second bias voltage circuit unit 122) that applies the forward bias voltage or the reverse bias voltage to the second diode; Equipped with The filter circuit comprises: a first filter section (first filter section 131) having a first inductor (first inductor 131a) and a first capacitor (first capacitor 131b) connected in series; a second filter section (second filter section 132) having a second inductor (second inductor 132a) and a second capacitor (second capacitor 132b) connected in series; Equipped with an end of the first filter section on the first inductor side is connected between an end of the first circuit and an anode terminal of the first diode; the other end of the first filter section on the first capacitor side is connected to the reference potential line; a connection point (connection point P4) between the first inductor and the first capacitor in the first filter section is connected to the first bias voltage circuit section; one end of the second filter section on the second inductor side is connected between the other end of the first circuit and the anode terminal of the second diode, the other end of the second filter section on the second capacitor side is connected to the reference potential line, a connection point (connection point P7) between the second inductor and the second capacitor in the second filter section is connected to the second bias voltage circuit section; On / off switching circuit.

[0086] According to (5), it is possible to prevent AC power input to the first circuit from flowing into the second circuit by the first filter section and the second filter section, which are LC filters that can be easily and simply configured.

[0087] (6) The on / off switching circuit according to (5), The filter circuit comprises: The power supply further includes a third inductor (third inductor 133), a fourth inductor (fourth inductor 134), and a fifth inductor (fifth inductor 135) having impedances greater than those of the first inductor and the second inductor, a connection point between the first inductor and the first capacitor in the first filter unit is connected to the first bias voltage circuit unit via the third inductor; a connection point between the second inductor and the second capacitor in the second filter section is connected to the second bias voltage circuit section via the fourth inductor, the other end of the first filter section on the first capacitor side and the other end of the second filter section on the second capacitor side are connected to the reference potential line via the fifth inductor. On / off switching circuit.

[0088] According to (6), the voltages applied to the first diode and the second diode can be balanced, so that it is possible to adapt to AC power having a larger AC voltage without improving the voltage resistance of each diode. [Explanation of symbols]

[0089] 100 On / off switching circuit 110 1st circuit 110in one end 110out other end 111 First Diode (Diode, First Diode) 112 Second FET (Diode, Second Diode) 120 2nd circuit 121 First bias voltage circuit section 122 Second bias voltage circuit section 130 Filter Circuit 131 First filter section 131a First inductor 131b First capacitor 132 Second filter section 132a Second inductor 132b Second capacitor 133 Third inductor 134 4th inductor 135 5th inductor 140 Control Unit P1, P4, P7 connection points

Claims

1. a first circuit having a pair of diodes whose cathode terminals or anode terminals are connected to each other and capable of outputting AC power input to one end from the other end; a second circuit that applies a forward bias voltage or a reverse bias voltage to each of the pair of diodes to turn the pair of diodes on and off; Equipped with the second circuit applies the same forward bias voltage or the same reverse bias voltage to each of the pair of diodes, thereby synchronously turning on and off the pair of diodes; On / off switching circuit.

2. 2. The on / off switching circuit according to claim 1, The cathode terminals of the pair of diodes are connected to each other, a connection point between the cathode terminals is connected to a reference potential line of the second circuit; On / off switching circuit.

3. 2. The on / off switching circuit according to claim 1, The pair of diodes are each a PIN diode. On / off switching circuit.

4. 4. An on / off switching circuit according to claim 1, the first circuit and the second circuit are connected via a filter circuit that prevents the AC power input to the first circuit from flowing into the second circuit; On / off switching circuit.

5. 5. An on / off switching circuit according to claim 4, the pair of diodes are configured by connecting cathode terminals of a first diode at one end of the first circuit and a second diode at the other end of the first circuit, a connection point between the cathode terminals is connected to a reference potential line of the second circuit; The second circuit is a first bias voltage circuit unit that applies the forward bias voltage or the reverse bias voltage to the first diode; a second bias voltage circuit unit that applies the forward bias voltage or the reverse bias voltage to the second diode; Equipped with The filter circuit comprises: a first filter section having a first inductor and a first capacitor connected in series; a second filter section having a second inductor and a second capacitor connected in series; Equipped with an end of the first filter section on the first inductor side is connected between an end of the first circuit and an anode terminal of the first diode; the other end of the first filter section on the first capacitor side is connected to the reference potential line; a connection point between the first inductor and the first capacitor in the first filter section is connected to the first bias voltage circuit section; one end of the second filter section on the second inductor side is connected between the other end of the first circuit and the anode terminal of the second diode, the other end of the second filter section on the second capacitor side is connected to the reference potential line; a connection point between the second inductor and the second capacitor in the second filter section is connected to the second bias voltage circuit section; On / off switching circuit.

6. 6. An on / off switching circuit according to claim 5, The filter circuit comprises: further comprising a third inductor, a fourth inductor, and a fifth inductor having impedances greater than those of the first inductor and the second inductor; a connection point between the first inductor and the first capacitor in the first filter unit is connected to the first bias voltage circuit unit via the third inductor, a connection point between the second inductor and the second capacitor in the second filter unit is connected to the second bias voltage circuit unit via the fourth inductor, the other end of the first filter section on the first capacitor side and the other end of the second filter section on the second capacitor side are connected to the reference potential line via the fifth inductor. On / off switching circuit.

Images