Ultra‐broadband quantification of CMOS varactors based on vector standing wave measurements in a non‐linear transmission line

Abstract

By near-filed scanning of a non-linear transmission line (NLTL), both the magnitude and the phase patterns of standing waves are measured. The patterns demonstrate the internal behavior of the NLTL such as inter-section mismatch, which is not observable by means of microwave network analysers at the device ports. With the analysis of standing waves, transmission line parameters such as the effective permittivity, the characteristics impedance, and varactor capacitances are quantified over a broad frequency range from 10 to 90 GHz.