GAIN VARIABLE AMPLIFIER CIRCUIT, AND TERMINAL PROVIDED WITH THE SAME

摘要

PROBLEM TO BE SOLVED: To provide a gain variable amplifier circuit with a wide range. SOLUTION: A GCA(gain control amplifier) control circuit 13 consists of a TCP(transmit power control) decision circuit 30, an adder 32, an RF linear interpolation circuit 35, and an IF linear interpolation circuit 37 or the like, TCP data are given to the TCP decision circuit 30, its output is given to the adder 32, where it is summed to a current transmission output, and a sum of the adder 32 is given to the RF linear interpolation circuit 35 and the IF linear interpolation circuit 37. An output terminal of the RF linear interpolation circuit 35 is connected to a gain control terminal of an RF-GCA 24, an output terminal of the IF linear interpolation circuit 37 is connected to a gain terminal of an IF-GCA 20, and the RF linear interpolation circuit 35 and the IF linear interpolation circuit 37 respectively and separately control the RF-GCA 24 and the IF-GCA 20. Thus, a wide range can be realized and the gain variable amplifier circuit with less noise can be realized.