| 摘要 |
PROBLEM TO BE SOLVED: To realize a transmission/reception common use system in which a transmission/reception changeover switch is not required. SOLUTION: Inputs resulting from feeding back negatively signals I', Q' to transmission base band signals I, Q at subtractors 2a, 2b via filters 3a, 3b are given to quadrature modulator 4, where a carrier from an oscillator 31 is quadrature modulated by the inputs to obtain a transmission modulation signal, the signal is given to an up-convert mixer 22, in which the signal is frequency-converted by a locally oscillated signal from an oscillator 32, the frequency-converted signal is given to a high output amplifier 5 via a filter 24a, in which the signal is amplified, and either of transmission output signals from a directional coupler 6 is transmitted via a branching filter 63 and a transmission reception common use antenna 62. A power combiner 65 combines the other distributed output signal and a received modulation signal via the transmission reception common use antenna 62 and the branching filter 63, its output is given to a down-covert mixer 23, its output signal is given via a filter 24b to quadrature demodulator 11, where the signal is quadrature demodulated by using a carrier from the oscillator 31 and from which demodulated and reception base band signals I', Q' and I'', Q'' are outputted. |
