Control of a power amplifier using high- and low-sensitivity detectors on the feedback path whose outputs are combined and compared with a ramp signal

摘要

A mobile radio communication apparatus comprises a power amplifier (102) for power-amplifying a transmission signal (103) into an amplified transmission signal which is transmitted through an antenna (101). A high-sensitivity detector (105) high-sensitivity detects the amplified transmission signal. The high-sensitivity detection signal is limited by a diode (107) to a predetermined voltage to be produced as a first output voltage signal. A low-sensitivity detector (110) low-sensitivity detects the amplified transmission signal. A predetermined offset voltage is superposed on the low-sensitivity detection signal to be produced as a second output voltage signal. The first and the second output voltage signals are combined into a combined output signal. A comparator (118) compares the combined output signal with a transmission ramp production signal supplied from a mobile radio communication apparatus control section. With reference to a comparison result, a dynamic range of the power amplifier is controlled. Note that buffers are provided in both detector loops in an embodiment and that the apparatus is particularly suitable for TDMA systems.