A Closed-Loop Impedance Tuner With Integrated Reflectometer and High-Voltage Tuning Switches

In this work, a closed-loop radio frequency (RF) frontend impedance tuning system with high-voltage impedance tuning switches monolithically integrated with an RF reflectometer is presented. An RF application-specific integrated circuit (ASIC) integrating a low-power scalar RF reflectometer and two RF tuning switches is designed and manufactured in ${90}{\,}\text{nm}$ RF SOI CMOS switch technology. A hardware prototype closed-loop tuning system is built with the designed ASIC along with a commercial impedance tuning IC, aiming for tuning at operating frequencies between 690 and ${900}{\,}\text {MHz}$ . The circuit can process signals with power greater than ${18}{\,}\text {dBm}$ , while the RF voltage handling capability reaches ${63}{\,}\text {V}$ with the linearity of $\text {IIP}_{{3}}={84}{\,}\text {dBm}$ in the signal path. The designed ASIC consumes ${46}{\,}{{\mu }\text {W}}$ and ${184}{\,}{{\mu }\text {W}}$ in idle and conversion mode, respectively.