BROAD BAND INTERFERENCE WAVE ELIMINATION DEVICE

摘要

PROBLEM TO BE SOLVED: To eliminate an interference wave from the same frequency or frequencies close to each other over a wide frequency range in a radio communication system where a transmission antenna and a reception antenna are separately installed. SOLUTION: In a broad band interference wave elimination device 10, a directional coupler 6 separates part of an output signal of a transmitter 1 as a cancellation signal, which is given to a compensation circuit 11 via a variable attenuator 7 and a variable phase shifter 8. The compensation circuit 11 has a transmission response characteristic to compensate a phase frequency characteristic of an interference wave cancellation loop consisting of the variable attenuator 7 and the variable phase shifter 8. The signal compensated by the compensation circuit 11 is given to a directional coupler 9 as a interference wave cancellation signal to cancel the interference wave of a frequency F1 from a transmission antenna 3 entering the reception antenna 4.