SNEAK CANCELER CIRCUIT, RADIO COMMUNICATION EQUIPMENT, AND SNEAK CANCELLATION METHOD

摘要

PROBLEM TO BE SOLVED: To provide a sneak canceler circuit and radio communication equipment containing the same, capable of reducing sneaking of transmitter signal into a reception circuit by using a simple and low-cost circuit configuration.SOLUTION: The sneak canceler circuit includes an LSI 2 containing a transmission section 21, a reception section 22, and an attenuation amount adjustment section 23, first and second couplers 3 and 4, an antenna 5, an attenuator 6, and a connector 7. A line length L1 of a first line 8 from a fourth terminal of the second coupler 4 to an input end of the connector 7 by way of the attenuator 6 is such a line length as causing no phase difference from the signal waveform of a transmitter signal S1 after a signal S4 just before entering the connector 7 has passed the second coupler 4, and a line length L2 of a second line 9 from a third terminal of the first coupler 3 to the input end of the connector 7 is such a line length as having a phase different from the signal waveform of a sneak signal S3 just before entering the connector 7 by 180 degrees, and as a result, the sneak signal S3 is canceled with the signal S4.