GAIN CONTROL METHOD, GAIN CONTROL CIRCUIT, RADIO TRANSMITTER, RADIO RECEIVER, AND RADIO MEASUREMENT EQUIPMENT

摘要

PROBLEM TO BE SOLVED: To provide a gain control circuit and a gain control method using the same, etc. with a simple circuit configuration, having a smooth phase variation produced in an input signal when adjusting the gain, and a small phase variation amount thereof. SOLUTION: A controller 116 obtains and retains respective characteristics of an ATT 112a through an ATT 112m in regard to the phase variation amount against an input signal attenuation amount; and calculates the combination of the input signal attenuation amount of the ATT 112a through the ATT 112m, which makes the least phase variation amount generated in the input signal when adjusting the gain of the gain control circuit 100, using an arithmetic circuit based on the characteristics. The controller 116 then inputs a set signal 115a through a set signal 115m to the ATT 112a to the ATT 112m, respectively, according to the combination of the calculated input signal attenuation amount. COPYRIGHT: (C)2005,JPO&NCIPI