Monolithically Integrated 200-GHz Double-Slot Antenna and Resistive Mixers in a GaAs-mHEMT MMIC Process

This paper presents the design and characterization of two resistive mixers integrated with a double-slot antenna in a 100-nm GaAs mHEMT technology. With RF frequency varying from 185 to 202 GHz, a typical conversion loss (
L c
) of 8.0 dB is measured for the single-ended mixer and a typical
L c
of 12.2 dB is obtained from one of the two IF outputs for the single-balanced mixer. Each mixer is integrated with a double-slot antenna and mounted on an Si lens. Incorporating the antenna gain and the conversion loss of the mixer, a typical receiver gain of 15.4 dB is achieved for the integrated antenna with single-ended mixer, and a typical receiver gain of 11.2 dB is obtained for the integrated antenna with single-balanced mixer by measuring one of the two IF outputs. In this paper, a novel method is also proposed and proved to evaluate a moderate to high noise figure (NF) device in millimeter/sub millimeter frequency band. The result shows that the single-ended mixer in this paper has an NF around 1.0 dB higher compared to its L
_c
, and the single-balanced one has an NF about 1.6 dB higher than its L
_c
at room-temperature operation.