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 <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${90}{\,}\text{nm}$</tex-math> </inline-formula> 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 <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${900}{\,}\text {MHz}$</tex-math> </inline-formula>. The circuit can process signals with power greater than <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${18}{\,}\text {dBm}$</tex-math> </inline-formula>, while the RF voltage handling capability reaches <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${63}{\,}\text {V}$</tex-math> </inline-formula> with the linearity of <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\text {IIP}_{{3}}={84}{\,}\text {dBm}$</tex-math> </inline-formula> in the signal path. The designed ASIC consumes <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${46}{\,}{{\mu }\text {W}}$</tex-math> </inline-formula> and <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${184}{\,}{{\mu }\text {W}}$</tex-math> </inline-formula> in idle and conversion mode, respectively.