JP2012182652A - Radio communication apparatus and high frequency switch circuit - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a radio communication apparatus and high frequency switch circuit capable of reducing a circuit scale and power consumption.SOLUTION: A radio communication apparatus 100 includes a shared antenna 101, matching circuits 110, 120, a high frequency switch circuit 130, a charge power reception circuit 140, and a transponder 150. The high frequency switch circuit 130 includes field effect transistors 131, 132, and a detector circuit. The source terminals of the field effect transistors 131, 132 are commonly connected. The detector circuit is connected to a common connection point, thereby to detect a high frequency signal which has been output from the drain terminal of the field effect transistor 131 and to apply detection voltage with the potential at the common connection point as reference to the gate terminals of the field effect transistors 131, 132. Impedance between the drain terminals of the field electric transistors 131, 132 is changed in accordance with the detection voltage.

Description

  The present invention relates to a radio communication device and a high frequency switch circuit.

  Antenna switches mounted on multiband mobile phones that can use multiple frequencies are composed of semiconductor elements such as field-effect transistors, but not a few nonlinear characteristics occur, and signals called harmonics are radiated unnecessarily from the antenna. May be. Since this harmonic may affect other communication devices, low distortion characteristics are required for an antenna switch mounted on a multiband mobile phone.

  Methods for reducing the distortion of an antenna switch include a method in which field effect transistors constituting a switch circuit are connected in multiple stages to reduce the voltage amplitude applied to the field effect transistor, and a method to increase the operating voltage of the field effect transistor. .

  Although the method of connecting the field effect transistors in multiple stages can be easily realized, the area of an IC (Integrated Circuit) chip becomes large, which is disadvantageous in terms of cost. The method of increasing the operating voltage of the field effect transistor has a limitation on the battery voltage of a mobile phone or the like. For this reason, there is a method in which a booster circuit is built in the antenna switch and the operating voltage is raised by boosting the power supply voltage (Patent Document 1).

  Patent Document 1 discloses a high-frequency switch circuit that can supply a voltage higher than an externally supplied power supply voltage to an antenna switch by including a booster circuit and can further suppress distortion. .

JP-A-11-55156

  The high-frequency switch circuit disclosed in Patent Document 1 configures a booster circuit using an oscillation circuit or the like, but in this configuration, power consumption for driving the oscillation circuit or the like that configures the booster circuit increases. Further, such a high-frequency switch circuit has a larger circuit scale than a high-frequency switch circuit that does not include a booster circuit.

  In addition, near field communication devices such as RFID (Radio Frequency IDentification) cards and non-contact charging devices that charge a battery by magnetic coupling or the like transmit power of several watts when switching signal paths. Compared to a conventional antenna switch, the signal voltage amplitude is as large as about 10 and several volts. For this reason, the high-frequency switch circuit using the booster circuit further increases in circuit scale and increases current consumption.

  The present invention has been made in view of the above circumstances, and an object thereof is to provide a radio communication device and a high-frequency switch circuit with a small circuit scale and low power consumption.

In order to achieve the above object, a wireless communication apparatus according to the first aspect of the present invention provides:
A wireless communication device comprising an antenna, a high-frequency switch circuit, a wireless communication circuit, and a power receiving circuit,
The high-frequency switch circuit and the wireless communication circuit are connected in parallel, the antenna, the wireless communication circuit and the power receiving circuit are connected in series,
The antenna outputs a high frequency signal received from an external device to the high frequency switch circuit,
The high-frequency switch circuit detects the high-frequency signal output from the antenna, and switches a path of the high-frequency signal according to a detection voltage;
When the radio communication circuit receives the high-frequency signal, it transmits a response signal to the external device via the antenna,
The power receiving circuit includes a battery, and upon receiving the high frequency signal, supplies the high frequency signal to the battery as charging power.
It is characterized by that.

In order to achieve the above object, a wireless communication apparatus according to the second aspect of the present invention provides:
A wireless communication device comprising an antenna, a high-frequency switch circuit, a first wireless communication circuit, and a second wireless communication circuit,
The antenna, the first wireless communication circuit, and the second wireless communication circuit are connected to the high-frequency switch circuit,
A bias voltage is applied to the high frequency switch circuit,
The antenna outputs a high frequency signal received from an external device to the high frequency switch circuit,
The high-frequency switch circuit switches a path of the high-frequency signal output from the antenna based on the bias voltage,
The first wireless communication circuit or the second wireless communication circuit receives the high-frequency signal;
It is characterized by that.

In order to achieve the above object, a high-frequency switch circuit according to a third aspect of the present invention includes:
A high frequency switch circuit comprising a first field effect transistor, a second field effect transistor, and a detection circuit,
The source terminal of the first field effect transistor and the source terminal of the second field effect transistor are connected in common,
The detection circuit is connected to a common connection point of the source terminals of the first field effect transistor and the second field effect transistor, and detects a high frequency signal output from the drain terminal of the first field effect transistor. Applying a detection voltage based on the potential of the common connection point to the gate terminal of the first field effect transistor and the gate terminal of the second field effect transistor;
The impedance between the drain terminals of the first field effect transistor and the second field effect transistor changes according to the detection voltage.
It is characterized by that.

  According to the present invention, the circuit scale can be reduced and the power consumption can be reduced.

1 is a circuit diagram illustrating an example of a wireless communication device including a high-frequency switch circuit according to a first embodiment of the present invention. 1 is an equivalent circuit diagram illustrating an example of a wireless communication device including a high-frequency switch circuit according to a first embodiment of the present invention. It is a circuit diagram which shows an example of a radio | wireless communication apparatus provided with the high frequency switch circuit which concerns on 2nd Embodiment of this invention. It is a circuit diagram which shows an example of a radio | wireless communication apparatus provided with the high frequency switch circuit which concerns on 3rd Embodiment of this invention. It is a circuit diagram which shows an example of a radio | wireless communication apparatus provided with the high frequency switch circuit which concerns on 4th Embodiment of this invention.

[First Embodiment]
A high-frequency switch circuit and a wireless communication device according to a first embodiment of the present invention will be described with reference to the drawings. As shown in FIG. 1, the wireless communication device 100 according to the present embodiment includes a shared antenna 101, matching circuits 110 and 120, a high frequency switch circuit 130, a charging power receiving circuit 140, and a responder 150. Has been. The wireless communication device 100 communicates with an external device by non-contact communication.

  The wireless communication device 100 has a configuration in which the shared antenna 101 is connected in series with the responder 150 and the charging power receiving circuit 140 via the matching circuit 110, and the responder 150 is connected in parallel with the high-frequency switch circuit 130 and the matching circuit 120. is there.

  The shared antenna 101 receives a carrier wave from the outside or transmits a carrier wave to the outside. The matching circuit 110 includes a capacitor 111, and the matching circuit 120 includes an inductor 121. The matching circuits 110 and 120 perform impedance matching.

  The high frequency switch circuit 130 includes field effect transistors 131 and 132, bias resistors 133 and 134, detection diodes 135 and 136, a grounding capacitor 137, a smoothing capacitor 138, and a resistor 139. Switch the signal path. The detection diodes 135 and 136, the grounding capacitor 137, the smoothing capacitor 138, and the resistor 139 constitute a detection circuit.

  The source terminals of the field effect transistors 131 and 132 are connected in common. The anode of the detection diode 135 is connected to the common connection point of the field effect transistors 131 and 132, and the cathode of the detection diode 135 is grounded via the grounding capacitor 137 and further connected to the anode of the detection diode 136. . The cathode of the detection diode 136 is connected to a common connection point of the field effect transistors 131 and 132 via a parallel connection body of the smoothing capacitor 138 and the resistor 139, and further, the field effect transistor 131 is connected via the bias resistors 133 and 134. , 132 are connected to the gate terminals.

  The charging power receiving circuit 140 is composed of rectifying diodes 141 to 144, a smoothing capacitor 145, a charging control circuit 146, and a battery 147, and receives power for charging the battery. The rectifier diodes 141 to 144 constitute a full-wave rectifier circuit, and the rectified output terminal of the full-wave rectifier circuit is connected to the battery 147 via the smoothing capacitor 145 and the charge control circuit 146.

  The responder 150 includes wireless communication and a power receiving circuit, and generates response data for data transmitted by the carrier wave.

  As shown in FIG. 2, the impedance from the responder 150 to the shared antenna 101 side is a rectifier circuit composed of a parasitic capacitance 180 between the drain terminals of the field effect transistors 131 and 132 and rectifier diodes 141 to 144. Since the parasitic capacitance 190 is added, the matching circuit 120 becomes capacitive, and the matching circuit 120 can cancel the capacitive impedance by connecting the inductor 121, thereby achieving impedance matching.

  The above is the configuration of the wireless communication device 100.

  Next, the configuration of the external device will be described. As shown in FIG. 1, the interrogator 160 includes a wireless communication and power supply circuit 161 and a wireless communication antenna 162, and supplies power necessary for wireless communication with the responder 150 of the wireless communication device 100. To perform wireless communication with the wireless communication apparatus 100.

  The charging power supply device 170 includes an oscillation circuit 171, an amplification circuit 172, and a power transmission antenna 173. For example, the wireless communication device 100 is wirelessly coupled to the wireless communication device 100 in a non-contact manner. Electric power necessary for charging 100 batteries 147 is transmitted.

  The above is the configuration of the external device.

  By the way, the high frequency switch circuit 130 included in the wireless communication apparatus 100 switches the path of the high frequency signal by switching the field effect transistors 131 and 132 between the on state and the off state. Here, the gate terminal voltage necessary for controlling such a field effect transistor will be described.

In general, when Vrf is a voltage of a transmission or reception signal input to a high-frequency switch and Vth is a threshold voltage of a gate terminal at which the field effect transistor switches between an on state and an off state, a gate terminal necessary for controlling the field effect transistor The voltage Vgsw is as follows.
Vgsw> Vrf + Vth

  For example, the signal amplitude Vrf used for power transmission in a non-contact charging device that charges a battery of a portable device is about 10 and several volts. Further, since the threshold voltage Vth of the field effect transistor is about 2V or less, the gate terminal voltage Vgsw necessary for controlling the field effect transistor is required to be about 10 to 20V.

On the other hand, the configuration of the present embodiment is a configuration in which the detection voltage is applied with reference to the common connection point of the source terminals of the field effect transistor, so that the field effect is independent of the signal amplitude Vrf input to the high frequency switch circuit. Since a voltage generated by the detection circuit is always applied between the gate terminal and the source terminal of the transistor, the gate terminal voltage Vgsw necessary for controlling the field effect transistor is expressed by the following equation.
Vgsw> Vth

  Therefore, in this embodiment, since the gate terminal voltage required for control may be about 2 V, which is the threshold voltage of the field effect transistor, the conventional booster circuit can be used even with a high voltage amplitude as in a non-contact charging device. The current consumption can be reduced as compared with the case of using.

  Next, the operation of wireless communication between the wireless communication device 100 and the interrogator 160 will be described.

  The wireless communication and power supply circuit 161 of the interrogator 160 transmits the power that allows the responder 150 of the wireless communication device 100 to operate via the wireless communication antenna 162 using a carrier wave (for example, a 13.56 MHz band signal). To do. The transmission data is transmitted using a modulation scheme such as ASK (Amplitude Shift Keying), but is not limited to this, and GASK (Gaussian filtered ASK) or SSB-ASK (Single Side Band ASK) may be used. .

  At this time, when the wireless communication device 100 is at a short distance from the interrogator 160, the wireless communication device 100 receives the carrier wave signal from the interrogator 160 by the shared antenna 101.

  The carrier wave received by the wireless communication device 100 is detected by the detection diodes 135 and 136 via the field effect transistor 131 of the high-frequency switch circuit 130, smoothed by the smoothing capacitor 138, and further via the bias resistors 133 and 134. Applied to the gate terminals of the field effect transistors 131 and 132.

  The capacitance value of the grounding capacitor 137 is such a value that the field effect transistors 131 and 132 are not turned on by the detection voltage at this time. That is, the impedance between the drain terminals of the field effect transistors 131 and 132 becomes a large value according to the detection voltage of the detection circuit.

  For this reason, the carrier wave received by the wireless communication device 100 is applied to both ends of the responder 150 and the charging power receiving circuit 140, but the input of the charging power receiving circuit 140 is the impedance of the full-wave rectifying circuit by the rectifying diodes 141 to 144. Therefore, the value is much lower than the input impedance of the responder 150.

  Further, the received carrier wave is input to the responder 150 because the matching circuit 120 achieves impedance matching with the responder 150, so that most of the amplitude of the carrier wave is applied between the input terminals of the responder 150. The responder 150 converts the carrier wave into power by the power receiving circuit, generates response data for the transmission data by the responder 150 using the power, and returns the generated response data via the shared antenna 101. The returned data is received by the wireless communication and power supply circuit 161 of the interrogator 160 via the wireless communication antenna 162 of the interrogator 160.

  As the wireless communication device 100 operates in this way, wireless communication between the interrogator 160 and the wireless communication device 100 becomes possible.

  Next, an operation of transmitting power in a contactless manner between the wireless communication device 100 and the charging power supply device 170 will be described.

  The charging power supply device 170 oscillates a power transmission signal at a frequency (for example, 13.56 MHz) at which power is supplied by the oscillation circuit 171, amplifies the signal by the amplifier circuit 172, and transmits the power via the power transmission antenna 173.

  At this time, when the wireless communication device 100 is at a short distance from the charging power supply device 170, the wireless communication device 100 receives the power transmission signal from the charging power supply device 170 by the shared antenna 101. The power transmission signal from the charging power supply device 170 is about several watts, which is significantly higher than the carrier wave transmitted from the interrogator 160.

  As a result, the field effect transistors 131 and 132 are turned on by the detection voltages of the detection diodes 135 and 136, so that the input of the responder 150 is short-circuited. Accordingly, the received power transmission signal is input to the charging power receiving circuit 140.

  The power transmission signal input to the charging power receiving circuit 140 is rectified by a rectifying circuit including rectifying diodes 141 to 144, and is supplied as charging power to the battery 147 through the smoothing capacitor 145 and the charging control circuit 146.

  By operating the wireless communication device 100 in this way, power can be transmitted between the charging power supply device 170 and the wireless communication device 100 in a contactless manner.

  To summarize the operation of the wireless communication apparatus 100 described above, the wireless communication apparatus 100 switches to the path to the responder 150 when the power value of the received signal is small, and the charging power receiving circuit when the power value of the received signal is large. The route to 140 will be switched.

  The high-frequency switch circuit 130 constitutes a voltage doubler detection circuit with the detection diodes 135 and 136. Here, the operation of this voltage doubler detection circuit will be described.

  When a power transmission signal is received from the charging power supply device 170, the detection diode 135 is grounded at a high frequency with the grounding capacitor 137 via the drain terminal and the source terminal of the field effect transistor 131 in the off state. When the amplitude of the received power transmission signal is positive at the common connection point side of the field effect transistors 131 and 132 and negative at the ground side, the detection diode 135 is turned on, so the potential difference between both ends of the detection diode 135 is on the anode side. Slightly higher.

  In addition, when the amplitude of the received power transmission signal is negative on the common connection point side of the field effect transistors 131 and 132 and positive on the ground side, the detection diode 135 is turned off, so that the anode side of the detection diode 135 is on the negative side The cathode side is the positive electrode. Therefore, when the potentials at both ends of the detection diode 135 are averaged (detection voltage), the average potential is higher on the cathode side than on the anode side.

  Similarly, the detection voltage of the detection diode 136 is higher on the cathode side, but since the cathode of the detection diode 135 and the anode of the detection diode 136 are connected, the anode side of the detection diode 135 (field effect transistor 131, As a potential on the cathode side of the detection diode 136 viewed from the common connection point 132, a voltage twice as high as the detection voltage of the diode is output (double voltage detection). Thus, the voltage doubler detection circuit can obtain a high detection voltage with a relatively simple configuration.

  As described above, the wireless communication device 100 according to the present embodiment has a high-frequency switch circuit in the case of wireless communication that receives and responds to a carrier wave signal including power, and in the case of receiving non-contact charging power. The circuit scale can be reduced, and power supply can be reduced because the operation power supply is unnecessary.

[Second Embodiment]
A high-frequency switch circuit and a wireless communication device according to a second embodiment of the present invention will be described with reference to the drawings. In addition, the same code | symbol is attached | subjected about the component which is the structure and function similar to the radio | wireless communication apparatus 100 which concerns on 1st Embodiment, and description is abbreviate | omitted.

  As shown in FIG. 3, the wireless communication device 200 according to the present embodiment includes a shared antenna 101, matching circuits 110 and 120, a high frequency switch circuit 230, a charging power receiving circuit 140, a responder 150, and a control terminal. 201.

  The high frequency switch circuit 230 includes a field effect transistor 202 and a bias resistor 203 in addition to the configuration of the high frequency switch circuit 130 according to the first embodiment.

  The wireless communication apparatus 200 can control the grounding state of the grounding capacitor 137 by the field effect transistor 202 and control the detection operation of the detection diodes 135 and 136. That is, the grounding capacitor 137 is grounded through the field effect transistor 202 by applying a high-level bias voltage of about 2 V at which the field effect transistor 202 is turned on to the control terminal 201 of the high-frequency switch circuit 230.

  Therefore, for example, when the wireless communication device 200 receives a power transmission signal from the charging power supply device 170 as illustrated in FIG. 1, the field effect transistors 131 and 132 are detected by the voltages detected by the detection diodes 135 and 136. The battery is turned on, and a charging current can be supplied to the battery 147.

  On the other hand, even when the power transmission signal from the charging power supply device 170 is received, by setting the bias voltage of the control terminal 201 of the high frequency switch circuit 230 to a low level of 0 V, the field effect transistor 202 is turned off and grounding is performed. The working capacitor 137 is not grounded. For this reason, detection by the detection diodes 135 and 136 is hardly performed, and the field effect transistors 131 and 132 are turned off.

  Note that the basic operation of the wireless communication apparatus 200 is the same as that of the wireless communication apparatus 100 according to the first embodiment.

  As described above, the radio communication apparatus 200 according to the present embodiment can obtain the same effects as those of the first embodiment, and can switch the high-frequency switch circuit 230 with the control terminal 201. The path switching timing can be easily controlled, and the received signal can be controlled in detail.

[Third Embodiment]
A high-frequency switch circuit and a wireless communication device according to a third embodiment of the present invention will be described with reference to the drawings. In addition, the same code | symbol is attached | subjected about the component which is the structure and function similar to the radio | wireless communication apparatus 100 which concerns on 1st Embodiment, and description is abbreviate | omitted.

  As shown in FIG. 4, the wireless communication apparatus 300 according to this embodiment includes a shared antenna 101, matching circuits 110 and 120, a high-frequency switch circuit 130, a charging power receiving circuit 340, and a responder 150. Has been.

  In addition to the charging power receiving circuit 140 according to the first embodiment, the charging power receiving circuit 340 further includes an n-channel field effect transistor 301, a p-channel field effect transistor 302, bias resistors 303 and 305, and a load resistor 304. And.

  In the n-channel field effect transistor 301, the drain terminal is connected to the positive side of the output terminal of the rectifier circuit composed of the rectifier diodes 141 to 144 (the connection point between the cathode of the rectifier diode 142 and the cathode of 144) and the load resistor 304. The source terminal is connected to the negative side of the output terminal of the rectifier circuit (the connection point between the anode of the rectifier diode 141 and the anode of 143), and the gate terminal is connected to the cathode of the detector diode 136 and the bias resistor 303. Connect.

  In the p-channel field effect transistor 302, the source terminal is connected to the positive side of the output terminal of the rectifier circuit, the drain terminal is connected to the smoothing capacitor 145, and the gate terminal is connected to the drain terminal of the n-channel field effect transistor 301. Connection is made through a resistor 305.

  For example, when the wireless communication device 300 receives charging power from a charging power supply device 170 as shown in FIG. 1, the high-frequency switch circuit 130 is turned on, and the n-channel field effect transistor 301 is detected by the detection voltage of the high-frequency switch circuit 130. Is turned on.

  For this reason, the gate terminal potential of the p-channel field effect transistor 302 becomes a potential on the negative electrode side having a DC potential lower than the source terminal potential. Therefore, the p-channel field effect transistor 302 is turned on, and the charging control circuit 146 can receive charging power.

  Further, when charging power is not received, that is, when the high-frequency switch circuit 130 is in an off state, the n-channel field effect transistor 301 is in an off state. Therefore, the gate terminal of the p-channel field effect transistor 302 becomes equal to the positive-side source terminal potential, and the p-channel field effect transistor 302 is turned off.

  The basic operation of the wireless communication apparatus 300 is the same as that of the wireless communication apparatus 100 according to the first embodiment.

  As described above, the wireless communication apparatus 300 according to the present embodiment can obtain the same effects as those of the first embodiment. Further, when the wireless communication signal is received from the interrogator 160, the rectifier diodes 141 to 144 are connected. As a result, the wireless communication signal leaks into the charging control circuit 146, so that deterioration in communication sensitivity can be suppressed.

[Fourth Embodiment]
A high-frequency switch circuit and a wireless communication device according to a fourth embodiment of the present invention will be described with reference to the drawings. In addition, the same code | symbol is attached | subjected about the component which is the structure and function similar to the radio | wireless communication apparatus 100 which concerns on 1st Embodiment, and description is abbreviate | omitted.

  As shown in FIG. 5, the wireless communication apparatus 400 according to the present embodiment includes a transmission / reception shared antenna 401, a reception-side control terminal 402, a transmission-side control terminal 403, a field effect transistor 404, a bias resistor 405, and a capacitance. 406, a transmission circuit 410, a reception circuit 420, and a high frequency switch circuit 430. The wireless communication apparatus 400 employs a method of performing communication by repeating transmission and reception alternately using the same frequency for transmission and reception, such as a wireless LAN (Local Area Network).

  The transmission / reception antenna 401 is connected to the field effect transistor 404 and the high-frequency switch circuit 430 through a capacitor 406. The field effect transistor 404 is connected to the capacitor 406 and the receiving circuit 420. The high frequency switch circuit 430 is connected to the capacitor 406 and the transmission circuit 410. The reception side control terminal 402 is connected to the gate terminal of the field effect transistor 404 via the bias resistor 405, and the transmission side control terminal 403 is connected to the field effect transistor 202 via the bias resistor 203.

  Subsequently, a signal reception operation of the wireless communication apparatus 400 will be described.

  When receiving a signal transmitted from an external device from the antenna 401 for both transmission and reception, the wireless communication device 400 applies a high-level control voltage to the reception-side control terminal 402 and applies a low-level control voltage to the transmission-side control terminal 403. Apply. Accordingly, the field effect transistor 404 is turned on, and the field effect transistors 131 and 132 are turned off. Therefore, the receiving circuit 420 can receive the signal received by the antenna 401 for both transmission and reception.

  When transmitting a signal from the transmission circuit 410, the wireless communication apparatus 400 applies a low-level control voltage to the reception-side control terminal 402 and applies a high-level control voltage to the transmission-side control terminal 403. As a result, the detection circuit of the high-frequency switch circuit 430 can operate with the power of the transmission signal from the transmission circuit 410. The field effect transistors 131 and 132 are turned on by the detection voltages of the detection diodes 135 and 136, so that the transmission circuit 410 can transmit by the antenna 401 shared for transmission and reception via the capacitor 406.

  The basic operation of the high frequency switch circuit 430 is the same as that of the high frequency switch circuit 130 according to the first embodiment.

  As described above, the wireless communication apparatus 400 according to the present embodiment can obtain the same effects as those of the first embodiment, and further, by adopting the high-frequency switch circuit of the present invention as the switch circuit of the transmission circuit, The scale can be reduced and the current consumption can be reduced.

  In addition, this invention is not limited to the said embodiment, A various modification and application are possible. For example, the case where the high-frequency switch circuit according to the present invention is employed in the transmission / reception apparatus has been described, but the present invention is not limited to this, and may be employed only in the transmission apparatus or only in the reception apparatus.

  Note that the present invention can be variously modified and modified without departing from the broad meaning and scope of the present invention. Further, the above-described embodiment is for explaining the present invention, and does not limit the scope of the present invention. That is, the scope of the present invention is shown not by the embodiments but by the claims. Various modifications within the scope of the claims and within the scope of the equivalent invention are considered to be within the scope of the present invention.

  A part or all of the above embodiment can be described as in the following supplementary notes, but is not limited thereto.

(Appendix 1)
A wireless communication device comprising an antenna, a high-frequency switch circuit, a wireless communication circuit, and a power receiving circuit,
The high-frequency switch circuit and the wireless communication circuit are connected in parallel, the antenna, the wireless communication circuit and the power receiving circuit are connected in series,
The antenna outputs a high frequency signal received from an external device to the high frequency switch circuit,
The high-frequency switch circuit detects the high-frequency signal output from the antenna, and switches a path of the high-frequency signal according to a detection voltage;
When the radio communication circuit receives the high-frequency signal, it transmits a response signal to the external device via the antenna,
The power receiving circuit includes a battery, and upon receiving the high frequency signal, supplies the high frequency signal to the battery as charging power.
A wireless communication apparatus.

(Appendix 2)
The high-frequency switch circuit is
A high frequency switch circuit comprising a first field effect transistor, a second field effect transistor, and a detection circuit,
The source terminal of the first field effect transistor and the source terminal of the second field effect transistor are connected in common,
The detection circuit is connected to a common connection point of the source terminals of the first field effect transistor and the second field effect transistor, and detects a high frequency signal output from the drain terminal of the first field effect transistor. Applying a detection voltage based on the potential of the common connection point to the gate terminal of the first field effect transistor and the gate terminal of the second field effect transistor;
The impedance between the drain terminals of the first field effect transistor and the second field effect transistor changes according to the detection voltage.
The wireless communication apparatus according to Supplementary Note 1, wherein:

(Appendix 3)
The detection circuit includes a first detection diode, a second detection diode, a first capacitor, a second capacitor, and a first resistor,
An anode of the first detection diode is connected to the common connection point;
The cathode of the first detection diode is grounded via the first capacitor, and further connected to the anode of the second detection diode,
The cathode of the second detection diode is connected to the common connection point via a parallel connection body of the first resistor and the second capacitor, and further, the first detection resistor is connected to the first detection resistor via the first bias resistor. Connected to the gate terminal of the field effect transistor, and connected to the gate terminal of the second field effect transistor via a second bias resistor;
The wireless communication apparatus according to Supplementary Note 2, characterized in that.

(Appendix 4)
The high-frequency switch circuit further includes a third field effect transistor,
The third field effect transistor is connected to the first capacitor, a bias voltage is applied to a gate terminal of the third field effect transistor,
The detection circuit detects the high-frequency signal according to the bias voltage;
The wireless communication device according to attachment 3, wherein

(Appendix 5)
When the bias voltage is high level, the detection circuit detects the high-frequency signal, and when the bias voltage is low level, the detection circuit does not detect the high-frequency signal.
The wireless communication apparatus according to appendix 4, wherein:

(Appendix 6)
A first matching circuit and a second matching circuit;
The antenna is connected in series to the wireless communication circuit and the power receiving circuit via the first matching circuit,
The high-frequency switch circuit is connected in parallel to the second matching circuit;
The first matching circuit and the second matching circuit achieve impedance matching.
The wireless communication device according to any one of appendices 1 to 5, characterized in that:

(Appendix 7)
The wireless communication circuit includes a power receiving circuit,
The power receiving circuit converts the high frequency signal into electric power when the wireless communication circuit receives the high frequency signal.
The wireless communication device according to any one of appendices 1 to 6, characterized in that:

(Appendix 8)
The power receiving circuit includes a rectifier circuit, a smoothing capacitor, and a charge control circuit,
The rectified output of the rectifier circuit is connected to the battery via the smoothing capacitor and the charge control circuit.
The wireless communication apparatus according to any one of appendices 1 to 7, wherein

(Appendix 9)
A wireless communication device comprising an antenna, a high-frequency switch circuit, a first wireless communication circuit, and a second wireless communication circuit,
The antenna, the first wireless communication circuit, and the second wireless communication circuit are connected to the high-frequency switch circuit,
A bias voltage is applied to the high frequency switch circuit,
The antenna outputs a high frequency signal received from an external device to the high frequency switch circuit,
The high-frequency switch circuit switches a path of the high-frequency signal output from the antenna based on the bias voltage,
The first wireless communication circuit or the second wireless communication circuit receives the high-frequency signal;
A wireless communication apparatus.

(Appendix 10)
A high frequency switch circuit comprising a first field effect transistor, a second field effect transistor, and a detection circuit,
The source terminal of the first field effect transistor and the source terminal of the second field effect transistor are connected in common,
The detection circuit is connected to a common connection point of the source terminals of the first field effect transistor and the second field effect transistor, and detects a high frequency signal output from the drain terminal of the first field effect transistor. Applying a detection voltage based on the potential of the common connection point to the gate terminal of the first field effect transistor and the gate terminal of the second field effect transistor;
The impedance between the drain terminals of the first field effect transistor and the second field effect transistor changes according to the detection voltage.
A high-frequency switch circuit characterized by that.

(Appendix 11)
The detection circuit includes a first detection diode, a second detection diode, a first capacitor, a second capacitor, and a first resistor,
An anode of the first detection diode is connected to the common connection point;
The cathode of the first detection diode is grounded via the first capacitor, and further connected to the anode of the second detection diode,
The cathode of the second detection diode is connected to the common connection point via a parallel connection body of the first resistor and the second capacitor, and further, the first detection resistor is connected to the first detection resistor via the first bias resistor. Connected to the gate terminal of the field effect transistor, and connected to the gate terminal of the second field effect transistor via a second bias resistor;
Appendix 10 is a high-frequency switch circuit.

(Appendix 12)
The high-frequency switch circuit further includes a third field effect transistor,
The third field effect transistor is connected to the first capacitor, a bias voltage is applied to a gate terminal of the third field effect transistor,
The detection circuit detects the high-frequency signal according to the bias voltage;
The high-frequency switch circuit according to appendix 11, wherein:

(Appendix 13)
When the bias voltage is high level, the detection circuit detects the high-frequency signal, and when the bias voltage is low level, the detection circuit does not detect the high-frequency signal.
Item 13. The high frequency switch circuit according to appendix 12.

(Appendix 14)
The power receiving circuit further includes a fourth field effect transistor and a fifth field effect transistor,
In the fourth field effect transistor, the drain terminal is connected to the positive side of the output terminal of the rectifier circuit, the source terminal is connected to the negative side of the output terminal of the rectifier circuit, and the gate terminal is used for the second detection. Connected to the cathode of the diode,
In the fifth field effect transistor, the drain terminal is connected to the smoothing capacitor, the source terminal is connected to the positive side of the output terminal of the rectifier circuit, and the gate terminal is connected to the drain terminal of the fourth field effect transistor. Connected,
The wireless communication apparatus according to appendix 8, wherein

100, 200, 300, 400 Wireless communication device 101, 401 Shared antenna 110, 120 Matching circuit 111, 406 Capacitance 121 Inductor 130, 230, 430 High-frequency switch circuit 131, 132, 202, 404 Field effect transistor 133, 134, 203, 303, 305, 405 Bias resistor 135, 136 Detection diode 137 Grounding capacitor 138, 145 Smoothing capacitor 139 Resistor 140, 340 Charging power receiving circuit 141, 142, 143, 144 Rectifier diode 146 Charging control circuit 147 Battery 150 Response 160 Interrogator 161 Wireless communication and power supply circuit 162 Wireless communication antenna 170 Charging power supply device 171 Oscillation circuit 172 Amplification circuit 173 Power transmission antennas 180 and 190 Parasitic capacitance 201 Control terminal 01 n-channel type field effect transistor 302 p-channel type field effect transistor 304 load resistor 402 receiving-side control terminal 403 transmitting-side control terminal 410 transmitting circuit 420 receiving circuit

Claims (10)

A wireless communication device comprising an antenna, a high-frequency switch circuit, a wireless communication circuit, and a power receiving circuit,
The high-frequency switch circuit and the wireless communication circuit are connected in parallel, the antenna, the wireless communication circuit and the power receiving circuit are connected in series,
The antenna outputs a high frequency signal received from an external device to the high frequency switch circuit,
The high-frequency switch circuit detects the high-frequency signal output from the antenna, and switches a path of the high-frequency signal according to a detection voltage;
When the radio communication circuit receives the high-frequency signal, it transmits a response signal to the external device via the antenna,
The power receiving circuit includes a battery, and upon receiving the high frequency signal, supplies the high frequency signal to the battery as charging power.
A wireless communication apparatus. The high-frequency switch circuit is
A high frequency switch circuit comprising a first field effect transistor, a second field effect transistor, and a detection circuit,
The source terminal of the first field effect transistor and the source terminal of the second field effect transistor are connected in common,
The detection circuit is connected to a common connection point of the source terminals of the first field effect transistor and the second field effect transistor, and detects a high frequency signal output from the drain terminal of the first field effect transistor. Applying a detection voltage based on the potential of the common connection point to the gate terminal of the first field effect transistor and the gate terminal of the second field effect transistor;
The impedance between the drain terminals of the first field effect transistor and the second field effect transistor changes according to the detection voltage.
The wireless communication apparatus according to claim 1. The detection circuit includes a first detection diode, a second detection diode, a first capacitor, a second capacitor, and a first resistor,
An anode of the first detection diode is connected to the common connection point;
The cathode of the first detection diode is grounded via the first capacitor, and further connected to the anode of the second detection diode,
The cathode of the second detection diode is connected to the common connection point via a parallel connection body of the first resistor and the second capacitor, and further, the first detection resistor is connected to the first detection resistor via the first bias resistor. Connected to the gate terminal of the field effect transistor, and connected to the gate terminal of the second field effect transistor via a second bias resistor;
The wireless communication apparatus according to claim 2. The high-frequency switch circuit further includes a third field effect transistor,
The third field effect transistor is connected to the first capacitor, a bias voltage is applied to a gate terminal of the third field effect transistor,
The detection circuit detects the high-frequency signal according to the bias voltage;
The wireless communication apparatus according to claim 3. When the bias voltage is high level, the detection circuit detects the high-frequency signal, and when the bias voltage is low level, the detection circuit does not detect the high-frequency signal.
The wireless communication apparatus according to claim 4. A first matching circuit and a second matching circuit;
The antenna is connected in series to the wireless communication circuit and the power receiving circuit via the first matching circuit,
The high-frequency switch circuit is connected in parallel to the second matching circuit;
The first matching circuit and the second matching circuit achieve impedance matching.
The wireless communication apparatus according to claim 1, wherein the wireless communication apparatus is a wireless communication apparatus. The wireless communication circuit includes a power receiving circuit,
The power receiving circuit converts the high frequency signal into electric power when the wireless communication circuit receives the high frequency signal.
The wireless communication apparatus according to claim 1, wherein the wireless communication apparatus is a wireless communication apparatus. The power receiving circuit includes a rectifier circuit, a smoothing capacitor, and a charge control circuit,
The rectified output of the rectifier circuit is connected to the battery via the smoothing capacitor and the charge control circuit.
The wireless communication device according to claim 1, wherein the wireless communication device is a wireless communication device. A wireless communication device comprising an antenna, a high-frequency switch circuit, a first wireless communication circuit, and a second wireless communication circuit,
The antenna, the first wireless communication circuit, and the second wireless communication circuit are connected to the high-frequency switch circuit,
A bias voltage is applied to the high frequency switch circuit,
The antenna outputs a high frequency signal received from an external device to the high frequency switch circuit,
The high-frequency switch circuit switches a path of the high-frequency signal output from the antenna based on the bias voltage,
The first wireless communication circuit or the second wireless communication circuit receives the high-frequency signal;
A wireless communication apparatus. A high frequency switch circuit comprising a first field effect transistor, a second field effect transistor, and a detection circuit,
The source terminal of the first field effect transistor and the source terminal of the second field effect transistor are connected in common,
The detection circuit is connected to a common connection point of the source terminals of the first field effect transistor and the second field effect transistor, and detects a high frequency signal output from the drain terminal of the first field effect transistor. Applying a detection voltage based on the potential of the common connection point to the gate terminal of the first field effect transistor and the gate terminal of the second field effect transistor;
The impedance between the drain terminals of the first field effect transistor and the second field effect transistor changes according to the detection voltage.
A high-frequency switch circuit characterized by that.

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