A radio communication apparatus comprising: a modulator configured to modulate a transmission signal with a transmission frequency to generate a modulated transmission signal; a demodulator configured to demodulate a modulated reception signal with a reception frequency different from the transmission frequency to generate a reception signal; and at least one transmission and reception set connected to the modulator and the demodulator, and configured to transmit the modulated transmission signal and to receive the modulated reception signal, the transmission and reception set comprising: a transmission and reception antenna configured to transmit the modulated transmission signal and to receive the modulated reception signal; a reception antenna configured to receive the modulated reception signal; a transmission filter interposed between the modulator and the transmission and reception antennas, and configured to pass the modulated transmission signal generated by the modulator; a reception filter interposed between the transmission and reception antenna and the demodulator and between the reception antenna and the demodulator, and configured to pass the modulated reception signal received at the transmission and reception antenna and the reception antenna; a first circulator configured to direct the modulated reception signal received at the transmission and reception antenna to the reception filter; and a second circulator configured to direct the modulated reception signal received at the reception antenna to the reception filter. a modulator configured to modulate a transmission signal with a transmission frequency to generate a modulated transmission signal; a demodulator configured to demodulate a modulated reception signal with a reception frequency different from the transmission frequency to generate a reception signal; and at least one transmission and reception set connected to the modulator and the demodulator, and configured to transmit the modulated transmission signal and to receive the modulated reception signal, the transmission and reception set comprising: a transmission and reception antenna configured to transmit the modulated transmission signal and to receive the modulated reception signal; a reception antenna configured to receive the modulated reception signal; a transmission filter interposed between the modulator and the transmission and reception antennas, and configured to pass the modulated transmission signal generated by the modulator; a reception filter interposed between the transmission and reception antenna and the demodulator and between the reception antenna and the demodulator, and configured to pass the modulated reception signal received at the transmission and reception antenna and the reception antenna; a first circulator configured to direct the modulated reception signal received at the transmission and reception antenna to the reception filter; and a second circulator configured to direct the modulated reception signal received at the reception antenna to the reception filter. a transmission and reception antenna configured to transmit the modulated transmission signal and to receive the modulated reception signal; a reception antenna configured to receive the modulated reception signal; a transmission filter interposed between the modulator and the transmission and reception antennas, and configured to pass the modulated transmission signal generated by the modulator; a reception filter interposed between the transmission and reception antenna and the demodulator and between the reception antenna and the demodulator, and configured to pass the modulated reception signal received at the transmission and reception antenna and the reception antenna; a first circulator configured to direct the modulated reception signal received at the transmission and reception antenna to the reception filter; and a second circulator configured to direct the modulated reception signal received at the reception antenna to the reception filter.