Design of a G-band detector based on zero-bias Schottky diodes

This paper proposes a high-sensitivity G-band detector module based on zero-bias Schottky diodes for direct detection radiometer receivers. To achieve a compact inline configuration with superior performance, the design features a novel U-shaped reduced-height waveguide transition, a cascaded CMRC low-pass filter, and an optimized DC grounding structure. Following rigorous EM-circuit co-simulations, the fabricated module was experimentally characterized. Measurement results demonstrate that the detector achieves a peak voltage responsivity of 9400 V/W in the small-signal regime. Specifically, at the target center frequency of 166 GHz, a high responsivity of approximately 6000 V/W is realized. The detector also exhibits excellent linearity (R2 > 0.998) and flatness, validating its suitability for high-performance millimeter-wave sensing applications.