A Mixed-Signal Matching State Search Based Adaptive Antenna Tuning IC

A closed-loop adaptive antenna tuning unit operating from 850 MHz-2 GHz for multi-band, multi-mode radios is presented. Unlike previous approaches, the proposed module utilizes an analog mismatch detector and a closed-loop mixed-signal matching state search circuit, without the need for an A/D converter. The integrated module is designed and fabricated on a 0.18 CMOS process. When tested on a band-limited shorted patch antenna, the module can perform a scan of 4096 antenna matching states in 4.1 ms, and tune the antenna to a specified narrow instantaneous bandwidth over the entire frequency range.