Abstract:

Accurate calibration of Vector Network Analyzers (VNAs) remains a keystone for high-reliability characterization of RF and microwave devices, especially when dealing with embedded differential structures. This paper presents an advanced TRL (Thru-Reflect-Line) calibration technique precisely designed for devices with differential input and single-ended output integrated into measurement boards. The proposed method builds upon a previously introduced TRL framework tailored for two-port devices and extends its applicability to asymmetric three-port configurations using simulated or on-wafer characterized standards. Through a three-step calibration process involving sequential TRL setups and an impedance bridging scheme, all elements of the Z-parameter matrix—including the otherwise inaccessible Z21—are successfully extracted. Comprehensive simulations using Agilent ADS validate the effectiveness and robustness of the proposed technique. The outcomes confirm that this approach provides a scalable and accurate methodology for embedded system characterization, especially in scenarios where conventional calibration kits fall short due to size and layout constraints.