| 摘要 |
PURPOSE:To reduce automatically the interference signal independently of the variance of characteristics of the propagation path between transmitting and receiving antennas and a relay amplifier, by using a pilot signal. CONSTITUTION:The output of a pilot signal generator 9 is superimposed to a transmission signal and is supplied to a transmitting antenna 2. Pilot signal components are detected from the output of a receiving antenna 1 by a filter 11, and a detection output es=ei+ec is subjected to synchronous detection in synchronous detectors 15a and 15b on a basis of in-phase and orthogonal components of the pilot signal branched from the pilot signal generator 9. Detected in-phase components ex and orthogonal components ey are applied to voltage adders 16a and 16b, and a vector modulator consisting of an equiamplitude 4- phase distributor 8 and an electric variable attenuator 18 is driven by outputs of these adders 16a and 16b. Thus, a feedback signal ec which is the output of the vector modulator controls to cancel an interference signal ei. |
