Adaptive antenna matching.

摘要

In a mobile radio telephone, an adaptive impedance matching circuit (25) is positioned between a transmitting power amplifier (24) and a duplexer (18). The adaptive matching circuit (25) matches an antenna (17) to associated electronic circuitry, thereby optimising power transfer in an effort to maintain communication with a base station and to minimise power dissipation within the device itself. An adaptation algorithm is selected and implemented during idle periods when a reflection coefficient is identified as being large. The reactance of a passive pi network is incrementally modified and settings which achieve an optimum match are stored for subsequent use.