D-Band Reciprocal Passive Design and Analysis Based on Consecutive Single-Ended Two-Port Measurements

This work proposes and analyzes a methodology to characterize the scattering parameters of multiport passives up to 170 GHz by consecutive single-ended two-port measurements. The generalized methodology is based on duplicating the device under test with linear combinations of load and open terminations to create a system of equations that can be solved for full characterization. The methodology is applied to a D-band differential four-port quadrature hybrid (QH) coupler designed in 22-nm FDSOI technology. Measurement results are presented for even- and odd-mode and differential-mode over five samples. Moreover, a quantitative and qualitative study is presented to highlight the method’s sensitivity to variability in measurement, device under test, and terminations.