Patent ID: 6836671
Filing Date: 2004-12-28
Classification: H03F

Abstract:
A feed-forward amplification circuit for producing the compensated output signals of a base transceiver station (BTS) in a cellular radio network, said amplification circuit comprising:an amplifier arranged to receive an input signal including a control signal, within a predetermined frequency range, and to produce an amplified signal including said control signal, within said predetermined frequency range, wherein said predetermined frequency range lies within the operational range of the amplifier; phase shift means arranged to receive said input signal and said amplified signal and to introduce a relative phase shift between said input signal and said amplified signal to produce an error signal; control means for controlling said phase shift means in dependence on the relative phase difference between the control signal in said input signal and the control signal in said amplified signal; and combination means for combining said error signal with said amplified signals to produce said compensated output signal; wherein said control signal comprises a signal used for communication between the BTS and a transceiver terminal of the network, wherein said control means comprise a first selective detection means being selective to a predetermined frequency for detecting the control signal in said input signal, and a second selective detection means being selective to said predetermined frequency, for detecting the control signal in said amplified signal.