Adaptive Matching Network for Antenna Mismatch Correction

The power amplifier is generally considered to be one of the most power-hungry components in the transceiver. Therefore its efficiency is major point of concern, not only in normal operation but also in the presence of antenna mismatch, when the varying load offered to power amplifier stage can result in severe efficiency degradation. The feasibility of a varactor-based adaptive matching network for antenna mismatch correction is investigated. A LC-resonator-based Π-section network is optimized for its performance, in terms of operation power gain, Smith Chart coverage, and effective capacitance tuning range of the varactors. It is shown that mismatch loading conditions, with a voltage standing wave ratio (VSWR) of 10, can be properly corrected back to the optimal matching condition (Γ(subscript Latage)=0), while providing a relatively high linearity and operating power gain, which ensures the high efficiency operation of the power amplifier.