Enhanced Accuracy in On-Wafer Noise Figure Measurements at Sub-Terahertz Frequencies

This paper delves into the precise on-wafer measurement of the noise figure (NF) of active circuits operating at millimetre-wave and sub-Terahertz frequencies. The focus lies on addressing the inherent challenge of the source impedance deviation at the input port plane of the die-under-test (DUT) from a matched load, a factor that significantly impacts the accuracy of NF measurements. The proposed testing system features an automated source tuner designed to counteract the non-idealities of ancillary components, including probes, cables, noise sources, switches, adapters, and frequency extenders, contributing to the impedance deviation. The testing system enables the measurement of the noise parameters of the DUT, allowing for the subsequent deduction of its noise figure. To validate its efficacy, the designed testing system is applied to measure the NF of a D-band distributed low-noise amplifier. The obtained results affirm the superior accuracy of the designed testing system when compared to the conventional Y-factor method.