METHOD AND APPARATUS FOR SUPPRESSING INTERFERENCE USING ACTIVE SHIELDING TECHNIQUES

摘要

A method and apparatus are disclosed for suppressing interference in a radio frequency (RF) communication system using active shielding techniques. An opposing neutralizing signal is applied to actively neutralize stray signals in a microwave communication environment. An interfering or stray signal is detected using a sensing antenna, and the opposing neutralizing signal is generated in response thereto. The opposing neutralizing signal is applied to a signal neutralizing shield to shield any desired components or devices. The opposing neutralizing signal is approximately 180 degrees out of phase, and of equal magnitude to the detected interfering signal. A phase shifter/null feedback device receives the detected stray signal, if any, and adaptively adjusts the phase and magnitude of the opposing neutralizing signal. In one embodiment, the phase shifter/null feedback device includes an integrator that generates a DC value that is proportional to the energy of the interfering signal. The DC value i s applied to a voltage controlled oscillator (VCO) using known feedback techniques to adjus t the phase or magnitude, or both, of the opposing neutralizing signal and to thereby minimize the DC value.