Abstract: A burst transmission booster and a burst transmission apparatus using the burst transmission booster. A low-power transmitter is responsive to a command from a base station to power-amplify and output transmission signals. If the commanded power level is too high to be realized solely by the low-power transmitter, the output of the low-power transmitter is boosted by the booster. The booster executes the boost such that the power level and waveform of the transmission signal will be coincident with or substantially coincident with the level and waveform of a given reference burst wave.

Abstract: A frequency synthesizer is designed to modify voltage value data read out of a memory in accordance with the output voltage of a filter, and apply a d.c. voltage corresponding to the modified data to a second variable-capacitance diode at the control input of a VCO, thereby allowing the VCO frequency switching without imposing a significant fluctuation of the application voltage to a first variable-capacitance diode and accomplishing a short channel switching time and stable operation against temperature fluctuation. The device is further designed to supply a voltage setup value read out of the memory to the second variable-capacitance diode thereby to reduce the frequency matching time at channel switching, and to determine such another voltage setup value as to reduce the time of phase matching based on the trend of change in the filter output voltage and supply the value to the second variable-capacitance diode.