Transmission output power control device for use in a burst transmitter and control method

A transmission output power control device for use in a dual-mode burst transmitter using a constant envelope modulation system and an amplitude modulation system, comprising:

• an l/Q signal amplitude control portion for variably controlling the shape of a rise and a fall of a waveform of a baseband signal and its burst transmission time from the end of the rise to the beginning of the fall in accordance with a modulation system signal;
• a modulator for modulating the baseband signal controlled in said I/Q signal amplitude control portion into a high-frequency signal in accordance with said modulation system signal;
• an amplifier for amplifying said high-frequency signal modulated in said modulator;
• and
• control voltage signal selecting means for outputting a predetermined constant voltage which is determined by said modulation system signal and a transmission power level signal, so as to control an output power of said amplifier.

A transmission output power control device for use in a dual-mode burst transmitter using a constant envelope modulation system and an amplitude modulation system, comprising:

• an I/Q signal amplitude control portion for controlling the shape of a rise and a fall of a waveform of a baseband signal and its burst transmission time from the end of the rise to the beginning of the fall in accordance with a modulation system signal;
• a modulator for modulating said baseband signal controlled in said I/Q signal amplitude control portion into a high-frequency signal in accordance with said modulation system signal;
• an amplifier for amplifying said high-frequency signal modulated in said modulator;
• a detector for detecting an transmission output power outputted from said amplifier;
• and
• a signal processing portion for outputting a control voltage to said amplifier in accordance with a signal from said detector in such a way as to make said transmission output power attain a target output power, obtaining a difference between a target control voltage and said control voltage with which said transmission output power attained said target output power, and controlling said I/Q signal amplitude control portion so that the shape of the rise and the fall of the waveform of said baseband signal and the burst transmission time from the end of the rise to the beginning of the fall are varied in accordance with said difference.