Abstract: A transmission circuit includes a first impedance circuit, a second impedance circuit, and a phase shifter. Each of the first impedance circuit and the second impedance circuit includes a register circuitry and a control circuitry that controls a resistance value of the register circuitry. The first impedance circuit is configured to output a reflected wave of an input signal to the phase shifter. The phase shifter is configured to shift a phase of the input signal to input the input signal to the first impedance circuit and to shift a phase of the reflected wave of the input signal output from the first impedance circuit to output the reflected wave to the combiner circuit. The second impedance circuit is configured to output the reflected wave of the input signal to the combiner circuit.

Abstract: A combiner circuit includes a transmission circuit to be connected to an antenna, and a control circuit configured to control impedance of the transmission circuit. The transmission circuit includes multiple impedance circuits having different impedances from each other, and multiple switch elements, each of which is connected to a corresponding one of the multiple impedance circuits. The control circuit includes multiple comparators, each of which is connected to a corresponding one of the multiple switch elements, and a voltage divider circuit including multiple resistive elements, each of which is configured to divide an input reference voltage and output a divided voltage power to a corresponding one of the multiple comparators.

Abstract: A transmission circuit includes: a plurality of impedance circuits having impedances different from each other, a plurality of first switch elements, any one of which is being connected to a respective one of the plurality of impedance circuits, and a first control circuit configured to control opening and closing of the plurality of first switch elements. The first control circuit is configured to be controllable to selectively change the opening and closing of the plurality of first switch elements and to rotate a reflection coefficient of an output terminal on an antenna side of the transmission circuit in a complex plane.