| 摘要 |
PROBLEM TO BE SOLVED: To suppress gain variation in accordance with manufacturing dispersion, temperature fluctuation and supply voltage fluctuation or the like while assuring low noise characteristics and high saturation characteristics without mounting a step type variable attenuator.SOLUTION: This high frequency amplifier circuit includes: a gain calculation part 11 which normalizes detected voltage A output from an input power detection circuit 7 according to ambient temperature, normalizes detected voltage B output from an output power detection circuit 8 to calculate a gain by dividing the normalized voltage B of the detected voltage B by the normalized voltage A of the detected voltage A, and a variable attenuator control circuit 13 controls an attenuation amount of a high frequency signal in the variable attenuator 5 so that the gain calculated by the gain calculation part 11 may match the desired gain. |
