Patent ID: 7541865

Claim:
An EER modulation amplifier that outputs a desired modulated and amplified signal from a high frequency amplification section by separating a phase signal and an amplitude signal from an inputted high frequency signal, amplifying the signals individually, setting the amplified phase signal as a gate voltage of the high frequency amplification section, and controlling a drain voltage of the high frequency amplification section based on the amplified amplitude signal, the EER modulation amplifier comprising: a drain voltage generating section that generates a drain voltage according to the amplitude signal and supplies the drain voltage to a drain terminal of the high frequency amplification section; a drain voltage determining section that determines a magnitude of the drain voltage in comparison to a first reference voltage set in advance; and a gate voltage control section that holds an initially set first gate voltage when the drain voltage is lower than the first reference voltage, and makes the gate voltage of the high frequency amplification section variable according to the drain voltage when the drain voltage is higher than the first reference voltage.