An impedance sensor for MEMS adaptive antenna matching

We propose a new calibration mechanism for passive adaptive cellular antenna matching network containing MEMS-based tunable devices. To avoid expensive and bulky couplers and reference circuitry, the tuner contains voltage and current sensors inserted before the antenna matching network. The sensed complex impedance generates 2-bit update controls for the tuning algorithm, which drives the MEMS-based tunable devices. The impedance sensing IC is designed to operate in the frequency range of 1.7–2.7 GHz and the clock frequency is 50 kHz.