| 摘要 |
A transmitting device is provided, which is capable of outputting a modulated wave which suffers little deterioration in modulation accuracy, spectrum and the like, even in the case of using a high-frequency power amplifier in which the fluctuation in phase difference between input and output is large when a bias voltage is changed. A complex number table ( 6 ) outputs a complex number that compensates for a phase shift of a high-frequency power amplifier ( 5 ) in accordance with the value of the amplitude component of a modulated signal output from an envelope detecting section ( 2 ). A complex number multiplier ( 7 ) outputs a phase-compensated modulated signal to a quadrature modulator ( 4 ). An amplitude conversion table ( 8 ) converts the amplitude component output from the envelope detecting section into a value in a predetermined range that excludes zero. Based on this value, a voltage source ( 3 ) generates a bias voltage and provides the bias voltage to a power supply terminal of the high-frequency power amplifier. The high-frequency power amplifier is driven by the bias voltage, amplifies a high-frequency band phase-compensated modulated signal output from the quadrature modulator, and outputs a modulated wave whose amplitude and phase vary. |
