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.

Abstract: A feedforward distortion compensation amplifier includes an adjusting unit for adjusting a gain and a phase of an input signal, a first amplifier for amplifying a signal outputted from the adjusting unit, a delay unit for delaying the input signal, and a coupler for coupling a signal outputted from the delay unit to a signal outputted from the first amplifier. The feedforward distortion compensation amplifier further includes a first controller which detects a distortion component of the first amplifier to control an operation of the adjusting unit based on the distortion component, and a second controller which determines one distortion level from distortion levels based on a magnitude of the input signal, and compares the determined distortion level with the detected distortion component of the first amplifier to control an amplification rate of the first amplifier based on comparison results.

Abstract: A feedforward distortion compensation amplifier includes an adjusting unit for adjusting a gain and a phase of an input signal, a first amplifier for amplifying a signal outputted from the adjusting unit, a delay unit for delaying the input signal, and a coupler for coupling a signal outputted from the delay unit to a signal outputted from the first amplifier. The feedforward distortion compensation amplifier further includes a first controller which detects a distortion component of the first amplifier to control an operation of the adjusting unit based on the distortion component, and a second controller which determines one distortion level from distortion levels based on a magnitude of the input signal, and compares the determined distortion level with the detected distortion component of the first amplifier to control an amplification rate of the first amplifier based on comparison results.