DOI: 10.1109/TMTT.2026.3651686   IEEEXplore: https://ieeexplore.ieee.org/document/11353344

Method to characterize differential multiport passive structures

110 – 170 GHz (D-band)

Consecutive single-ended measurements of the multiport passive structure under varying port terminations result in a system of equations that can be solved to characterize the device under test (DUT). The proposed generic methodology is validated for a coupled-line based quadrature hybrid and includes the following analysis techniques to investigate non-idealities and their impact on the error bounds: – DUT-specific analysis on measurement impairments to ensure the measured phase imbalance is physical. – Sensitivity analysis to real, capacitive, and combined load variation for estimated local termination resistor variation. – Asymmetry analysis to interconnect leads for port termination and port probing to determine induced offsets in phase error flatness and amplitude error.

Design and analysis of passive structures with commercially available measurement equipment.

>45 dB image rejection ratio (IRR) for simulations compared to five sample measurements.