Patent ID: 7899142
Filing Date: 2011-03-01
Classification: G01S,H04B

Abstract:
1. A leakage signal cancellation apparatus which cancels out a leakage signal which is leakage of a transmitted signal to a received signal in a transceiver, said apparatus comprising: a quadrature modulator or a vector modulator for dividing a part of said transmitted signal so as to generate a cancel signal; a signal comparing means for comparing an amplitude and a phase of the cancel signal generated by said quadrature modulator or said vector modulator with those of said received signal, and for outputting signals corresponding to results of the comparison; and a combiner for combining said received signal with an antiphase cancel signal whose phase is made to be opposite to that of the cancel signal outputted from said quadrature modulator or said vector modulator so as to cancel out said leakage signal, and wherein said quadrature modulator or said vector modulator generates said cancel signal on a basis of the output signals outputted by said signal comparing means, and said quadrature modulator or said vector modulator and said signal comparing means perform feedback control in such a manner that said cancel signal has a same amplitude as said leakage signal and is in phase with said leakage signal.