Patent ID: 8412095

Claim:
An apparatus for preventing oscillation of an amplifier by a coupled input between a first antenna and a second antenna in an antenna system, the amplifier generating an amplifier output, said apparatus comprising: a coupling simulator coupled to the amplifier to receive the amplified output, the coupling simulator generating a coupling simulator output having properties varying from output properties of the amplifier output by a pre-determined phase effect and a predetermined attenuation effect; a combining device coupled to the coupling simulator to receive the coupling simulator output, the combining device generating an amplifier input comprising the coupling simulator output; and a filter device coupled to each of the first antenna and the second antenna, wherein the amplifier output comprises a first amplifier output and a second amplifier output, one each directed to the first antenna and the second antenna, and wherein the coupling simulator generates the device output for each of the first amplifier output and the second amplifier output, wherein a value for each of the pre-determined phase effect and the pre-determined attenuation effect are assigned based on system parameters that describe the relationship between the first antenna and the second antenna.