A Study on Low-Cost Calibration Kits for U.FL Connector Systems

This paper presents a comparison between the use of custom-made, low-cost, U.FL-based, Short-Open-Load-Thru (SOLT) and Thru-Reflect-Line (TRL) calibration kits for Vector Network Analyzers (VNA). Due to the nearly complete absence of industry standard calibration kits employing U.FL, it is important to evaluate the accuracy of custom-made kits and their viability. The SOLT and TRL calibration kits tested were designed and constructed using a standard PCB corrosion process. Measurements and comparisons are made using off-the-shelf components with manufacturer scattering parameters, and printed-circuit-board (PCB) inductors electromagnetic (EM) simulations. The two-tier TRL calibration using the custom-made TRL kit presented generally better results than its SOLT counterpart from 400 MHz up to 2 GHz.