Radio-Frequency Impedance Tuners Based on All-Pass Networks Realized Using a Ferroelectric Integrated Passive Device Process

Impedance tuners are indispensable microwave components in either source-pull systems used for noise characterization or load-pull systems used for power characterization of transistors. A general-purpose impedance tuner that provides uniform coverage over the 4 quadrants of the Smith Chart are often implemented using one of the following circuit topologies: stub-based, loaded-line, and double-slug. Among them, the way how the double-slug tuner operates gives us an insight that systematic design of an impedance tuner can be divided into two parts: the design of a variable transformer and the design of a phase shifter. Ideally, the variable transformer only alters the magnitude of the reflection coefficient whereas the phase shifter only changes its angle.The goal of the proposed project, namely, “Radio-Frequency Impedance Tuners Based on All-Pass Networks Realized Using a Ferroelectric Integrated Passive Device Process,” is to develop a fully-integrated general-purpose impedance tuner that provides uniform coverage over the 4 quadrants of the Smith Chart. The design of the impedance tuner is divided into two parts: a variable transformer and a phase shifter. Both the variable transformer and the phase shifter will be implemented using magnetically coupled all-pass networks (MCAPNs). Moreover, we will use a home-made integrated passive device (IPD) process that features ferroelectric varactors to realize the impedance tuner. Finally, we plan to apply the impedance tuner to an adaptive impedance matching system.We plan to finish the proposed project in 1 year. In the first 4 months, we will focus on the development of the ferroelectric IPD process. In the middle 4 months, we will work on the fabrication and measurement of the capacitors, inductors, and resistors, as well as the analysis and design of the proposed circuits. In the last 4 months of the project period, the focus will be on the fabrication and measurement of the variable transformer, the phase shifter, and the impedance tuner. A fully-integrated 3.5-GHz impedance tuner will be presented at the end of the project to summarize the research and development efforts.