Feedforward amplifier

摘要

In the balance adjustment using a pilot signals in a distortion detector and a distortion canceller of a feed-forward amplifier for amplifying a CDMA transmission signal, a pilot code is spread by a long code different from that of the CDMA transmission signal to obtain the pilot signal. The pilot signal is converted to a signal of the transmission frequency band, and the converted signal is injected into the transmission signal at the input side of the amplifier. The pilot signal frequency band is detected from the output of an auxiliary amplifier of the distortion canceller and converted to the base band, thereafter being despread to detect the pilot signal (code). <IMAGE>