A fully-integrated SOI CMOS complex-impedance detector for matching network tuning in LTE power amplifier

This paper describes a wide dynamic-range and accurate complex-impedance detector for adaptive power amplifier load tuning systems. The detector IC, fabricated in a 130 nm SOI technology, consumes 7mA under 2.5V supply voltage. It can handle LTE signals with an input power from 0 dBm up to 40 dBm thanks to its variable attenuator system. System level measurements show that the detector has a very good accuracy in sensing the mismatched load impedance value in the VSWR region from 2:1 to 6:1.