Phase shifter, predistorter, and phased array antenna
There are provided a transformer including inductors, and variable capacitors. Capacitance values of the variable capacitors are controlled by a control signal. One end of the first inductor is connected to a reference potential, the first variable capacitor is connected in series between the other end of the first inductor and a first terminal, the second variable capacitor is connected in series between one end of the second inductor and a second terminal, the third variable capacitor is connected in series between the other end of the second inductor and a third terminal. The capacitance values of the variable capacitors are changed by the control signal to obtain a desired pass phase, a loss is small, and both functions of a single-phase-differential conversion and a phase shifter are realized.
1. A phase shifter, comprising:
a transformer which includes a first inductor and a second inductor, one end of the first inductor being connected to a reference potential;
a first variable capacitor connected in series between the other end of the first inductor and a first terminal;
a second variable capacitor connected in series between one end of the second inductor and a second terminal; and
a third variable capacitor connected in series between the other end of the second inductor and a third terminal,
wherein capacitance values of the first variable capacitor, the second variable capacitor, and the third variable capacitor are controlled based on a common control signal for controlling a phase difference between an input signal and an output signal, and
the phase difference between the input signal and the output signal is controlled by controlling a phase shift amount of the output signal, the phase shift amount being controlled by controlling capacitance values of the first variable capacitor, the second variable capacitor, and the third variable capacitor via variation in the common control signal.
2. The phase shifter according to claim 1 ,
wherein at least one of the first variable capacitor, the second variable capacitor and the third variable capacitor includes a variable capacitance diode whose capacitance value is controlled based on the common control signal.
3. The phase shifter according to claim 1 ,
wherein at least one of the first variable capacitor, the second variable capacitor and the third variable capacitor includes a varactor with a metal oxide semiconductor structure whose capacitance value is controlled based on the common control signal.
4. The phase shifter according to claim 1 ,
wherein at least one of the first variable capacitor, the second variable capacitor and the third variable capacitor includes a variable capacitor including a plurality of fixed capacitors and a plurality of switches configured to be controlled based on the common control signal.
5. The phase shifter according to claim 1 ,
wherein a single-phase signal input into the first terminal is converted into a differential signal and the differential signal is output from the second terminal and the third terminal.
6. The phase shifter according to claim 1 ,
wherein a differential signal input into the second terminal and the third terminal is converted into a single-phase signal and the single-phase signal is output from the first terminal.
7. A predistorter, comprising:
a phase shifter configured to control a phase difference between an input signal and an output signal in accordance with a common control signal; and
a control circuit configured to generate the common control signal that causes a first phase distortion in the phase shifter in accordance with an input power of a signal input into the phase shifter and to output the common control signal to the phase shifter, the first phase distortion being opposite to characteristic of a phase distortion caused in a circuit connected at a subsequent stage of the phase shifter,
wherein the phase shifter includes:
a transformer which includes a first inductor and a second inductor, one end of the first inductor being connected to a reference potential;
a first variable capacitor connected in series between the other end of the first inductor and a first terminal;
a second variable capacitor connected in series between one end of the second inductor and a second terminal; and
a third variable capacitor connected in series between the other end of the second inductor and a third terminal,
wherein capacitance values of the first variable capacitor, the second variable capacitor, and the third variable capacitor are controlled based on the common control signal, and
the phase difference between the input signal and the output signal is controlled by controlling a phase shift amount of the output signal, the phase shift amount being controlled by controlling capacitance values of the first variable capacitor, the second variable capacitor, and the third variable capacitor via variation in the common control signal.
8. The predistorter according to claim 7 ,
wherein the control circuit includes:
a power detection part configured to detect the input power of the signal input into the phase shifter; and
a control signal generation part configured to generate the common control signal and to output the common control signal to the phase shifter based on a detection result obtained by the power detection part.
9. The predistorter according to claim 8 ,
wherein at least one of the first variable capacitor, the second variable capacitor and the third variable capacitor includes variable capacitance diode; and
the control signal generation part generates a control voltage supplied to the variable capacitance diode on the basis of the detection result obtained by the power detection part.
10. The predistorter according to claim 8 ,
wherein at least one of the first variable capacitor, the second variable capacitor and the third variable capacitor includes a varactor with a metal oxide semiconductor structure whose capacitance value is controlled based on the common control signal.
11. The predistorter according to claim 8 ,
wherein at least one of the first variable capacitor, the second variable capacitor and the third variable capacitor includes a variable capacitor including a plurality of fixed capacitors and a plurality of switches configured to be controlled based on the common control signal.
12. A phased array antenna, comprising:
a plurality of sets of phase shifters configured to control a phase difference between an input signal and an output signal in accordance with a common control signal, amplifiers configured to amplify a signal whose phase is controlled by the phase shifter, and antennas configured to output the signal amplified by the amplifier; and
a control circuit configured to generate the common control signal for controlling the phase difference between the input signal and the output signal in the phase shifter in accordance with a phase difference of signals output from the antennas of the respective sets,
wherein each of the phase shifters includes:
a transformer which includes a first inductor and a second inductor, one end of the first inductor being connected to a reference potential;
a first variable capacitor connected in series between the other end of the first inductor and a first terminal;
a second variable capacitor connected in series between one end of the second inductor and a second terminal; and
a third variable capacitor connected in series between the other end of the second inductor and a third terminal,
wherein capacitance values of the first variable capacitor, the second variable capacitor, and the third variable capacitor are controlled based on the common control signal, and
the phase difference between the input signal and the output signal is controlled by controlling a phase shift amount of the output signal, the phase shift amount being controlled by controlling capacitance values of the first variable capacitor, the second variable capacitor, and the third variable capacitor via variation in the common control signal.
13. The phased array antenna according to claim 12 ,
wherein at least one of the first variable capacitor, the second variable capacitor and the third variable capacitor includes a variable capacitance diode whose capacitance value is controlled based on the common control signal.
14. The phased array antenna according to claim 12 ,
wherein at least one of the first variable capacitor, the second variable capacitor and the third variable capacitor includes a varactor with a metal oxide semiconductor structure whose capacitance value is controlled based on the common control signal.
15. The phased array antenna according to claim 12 ,
wherein at least one of the first variable capacitor, the second variable capacitor and the third variable capacitor includes a variable capacitor including a plurality of fixed capacitors and a plurality of switches configured to be controlled based on the common control signal.
16. A phased array antenna, comprising:
a plurality of sets of phase shifters configured to control a phase difference between an input signal and an output signal in accordance with a common control signal, and antennas; and
a control circuit configured to generate the common control signal for controlling the phase difference between the input signal and the output signal in the phase shifter,
wherein each of the phase shifters includes:
a transformer which includes a first inductor and a second inductor, one end of the first inductor being connected to a reference potential;
a first variable capacitor connected in series between the other end of the first inductor and a first terminal;
a second variable capacitor connected in series between one end of the second inductor and a second terminal; and
a third variable capacitor connected in series between the other end of the second inductor and a third terminal,
wherein capacitance values of the first variable capacitor, the second variable capacitor, and the third variable capacitor are controlled based on the common control signal, and
the phase difference between the input signal and the output signal is controlled by controlling a phase shift amount of the output signal, the phase shift amount being controlled by controlling capacitance values of the first variable capacitor, the second variable capacitor, and the third variable capacitor via variation in the common control signal.
17. The phased array antenna according to claim 16 ,
wherein at least one of the first variable capacitor, the second variable capacitor and the third variable capacitor includes a variable capacitance diode whose capacitance value is controlled based on the common control signal.
18. The phased array antenna according to claim 16 ,
wherein at least one of the first variable capacitor, the second variable capacitor and the third variable capacitor includes a varactor with a metal oxide semiconductor structure whose capacitance value is controlled based on the common control signal.
19. The phased array antenna according to claim 16 ,
wherein at least one of the first variable capacitor, the second variable capacitor and the third variable capacitor includes a variable capacitor including a plurality of fixed capacitors and a plurality of switches configured to be controlled based on the common control signal.