Abstract: In order to operate a power amplifier for synthesizing a plurality of amplifier circuits with high efficiency, the gate voltages of the field-effect transistors (FETs) of the plurality of amplifier circuits are adjusted according to an individual difference in saturated power between the amplifier circuits. Specifically, the output ratios of the amplifier circuits (AMP-4, 8) with low saturated power are reduced, whereas the output ratios of the amplifier circuits (AMP-2, 6) with high saturated power are increased. Thus, a device is operated with high efficiency.

Abstract: A combiner-divider includes a first impedance converter disposed between the first port and the second port, a second impedance converter disposed between the first port and the third port, and an isolation unit disposed between the second port and the third port. The isolation unit includes a balun formed of a first semi-rigid cable and a second semi-rigid cable, and terminating resistors. Each line length of the first impedance converter, the second impedance converter, and the third impedance converter corresponds to ¼ wavelength at a center frequency. A relationship of each impedance Ri of the second port and the third port, an impedance Ro of the first port, and each impedance W of the first impedance converter and the second impedance converters is expressed by W=(2×Ri×Ro)1/2.

Abstract: A combiner-divider includes a first impedance converter disposed between the first port and the second port, a second impedance converter disposed between the first port and the third port, and an isolation unit disposed between the second port and the third port. The isolation unit includes a balun formed of a first semi-rigid cable and a second semi-rigid cable, and terminating resistors. Each line length of the first impedance converter, the second impedance converter, and the third impedance converter corresponds to ¼ wavelength at a center frequency. A relationship of each impedance Ri of the second port and the third port, an impedance Ro of the first port, and each impedance W of the first impedance converter and the second impedance converters is expressed by W=(2×Ri×Ro)½.

Abstract: A Wilkinson combiner includes: a plurality of splitting units that splits signals inputted from two ports; an isolating unit that connects one ends of the signals split at the plurality of splitting units to each other; and a combiner that connects other ends of the signals split at the plurality of splitting units to each other and outputs a combined signal. The isolating unit balun-connects the connected signals to each other using a balun circuit, short-circuits the balun-connected one end, and terminates the balun-connected other end using a terminator.

Abstract: A Wilkinson combiner includes: a plurality of splitting units that splits signals inputted from two ports; an isolating unit that connects one ends of the signals split at the plurality of splitting units to each other; and a combiner that connects other ends of the signals split at the plurality of splitting units to each other and outputs a combined signal. The isolating unit balun-connects the connected signals to each other using a balun circuit, short-circuits the balun-connected one end, and terminates the balun-connected other end using a terminator.