HIGH-FREQUENCY INTEGRATED CIRCUIT FOR HIGH-FREQUENCY RADIO TRANSMITTER-RECEIVER SUPPRESSED IN INFLUENCE OF HIGH-FREQUENCY POWER LEAKAGE

摘要

A low-pass filter (3;3a, 3b; 8:13; 14) which only passes signals in a band lower than that of high-frequency signal components is provided between a high-frequency signal processing circuit (2; PAi) which processes the high-power signal of an RF front end section (RFFP) for processing the high-frequency signal of a portable telephone set and a control circuit (1: GVC) which controls the operation of the circuit (2). The circuit (2) functions as the transmission/reception switching circuit (2) of the telephone set and the circuit (1) functions as the transmission/reception control circuit (1) which determines the operation mode of the circuit (2). Alternatively, the circuit (2) functions as a power amplifier (PAi) and the control circuit (1) functions as the gate voltage control circuit (GVC) which adjusts the gain of the amplifier (PAi). Therefore, the influence of leakage of high-frequency components from the gate of a field effect transistor is suppressed, and the RF front end section (RRFP) can be constituted of a chip occupying a small area.