| 摘要 |
PROBLEM TO BE SOLVED: To provide a high frequency power amplifier that has no performance degradation as a phase control circuit of a simple structure and is compact and inexpensive. SOLUTION: A high frequency power amplifier of a digital radio communication device is equipped with a binarizing means 17 for binarizing, depending on whether a feedback signal exceeds a specified value or not, and a phase control means 18 for estimating a phase difference between an input signal and the feedback signal from an output signal of the binarizing means 17 and a signal that indicates a rising timing of a burst signal and outputs a control signal of a phase shifting means 8. At the time of rising of the burst signal of a transmission circuit, a sampling is applied to an input baseband signal and a feedback baseband signal, an intersected point on an I axis or a Q axis of an IQ virtual plane is detected, the phase difference between the input baseband signal and the feedback baseband signal is estimated by order of plus and minus of the intersected point to be detected and the amount of phase control of a phase shifter 8 is decided. |
