Low noise Sb-heterostructure diode detectors for W-band imaging arrays without RF amplification

The figure of merit for RF detectors, noise-equivalent power (NEP), is determined by the noise divided by the sensitivity. Thus, the challenge is to design a diode structure that has low junction resistance while maintaining a large nonlinearity. This work presents sensitivity and noise measurements for Sb-heterostructure backward diodes with varying barrier thicknesses and cross-sectional areas. Nominal diode areas are 2x2mm2 and 3x4mm2 with 15Å and 20Å barriers. The best NEP measured to date is 1.19 pW/rtHz at 36.5 GHz.