| 摘要 |
PROBLEM TO BE SOLVED: To provide a transmitter that uses 1st and 2nd input base band signals and 1st and 2nd feedback base band signals to correct the distortion of a transmission wave, solves a problem of demodulating a transmission signal leaked to an orthogonal demodulator into an erroneous feedback base band signal, decreases the number of filters to reduce the circuit scale and eliminates complicated and troublesome design taking a phase characteristic caused among the filters into account. SOLUTION: The transmitter is configured so that the orthogonal modulator 3 directly applies orthogonal modulation to an input base band signal with a transmission frequency to generate a transmission signal, a transmission signal including a distortion component generated in a power amplifier 6 or the like is partly fed back, the signal is once down-converted to have an intermediate frequency before applying orthogonal demodulation by an orthogonal demodulator 8 and orthogonal demodulation is applied to the feedback base band signal. Thus, leakage of the transmission signal to the orthogonal demodulator can be prevented, the number of filters can be decreased and the circuit design can be simplified. |
