Patent ID: 8351889
Filing Date: 2013-01-08
Classification: H04B

Abstract:
1. A method of filtering a signal to reduce signal power in at least one reject band, the method comprising: coupling a first portion of an input signal to a first vector modulator; coupling a second portion of the input signal to a second vector modulator; coupling a third portion of the input signal to a power amplifier and operating the power amplifier to provide an amplified signal; coupling a first portion of the amplified signal to the first vector modulator; coupling a second portion of the amplified signal to the second vector modulator; operating the first and second vector modulators in response to the coupled portions of the input signal and the coupled portions of the amplified signal to provide first and second cancellation signals respectively; coupling a pilot signal, the first and second cancellation signals and at least one portion of the amplified signal to a third vector modulator; operating the third vector modulator to provide a third cancellation signal; and combining the third cancellation signal with the amplified signal to reduce pilot and receive band noise in the amplified signal.