When switching over from a portable telephone system of 800 MHz band to a UWB communication system of 9 GHz band, depending upon a signal for changing over a high pass filter and a low pass filter, a reactance element, which is determined to be matching with a load Z of the high pass filter, is connected to an output terminal of a transmitting power amplifier. With this, it is possible to achieve a multi-band or multi-mode wireless receiver of using a frequency band from 800 MHz to 10 GHz, without an enlargement of a circuit scale and an increase of costs.