Cryogenic 160-GHz MMIC Heterodyne Receiver Module

A cryogenic 160-GHz MMIC heterodyne receiver module has demonstrated a system noise temperature of 100 K or less at 166 GHz. This module builds upon work previously described in “Development of a 150-GHz MMIC Module Prototype for Large-Scale CMB Radiation” (NPO-47664), NASA Tech Briefs, Vol. 35, No. 8 (August 2011), p. 27. In the original module, the local oscillator signal was saturating the MMIC low-noise amplifiers (LNAs) with power. In order to suppress the local oscillator signal from reaching the MMIC LNAs, the W-band (75–110 GHz) signal had to be filtered out before reaching 140–170 GHz. A bandpass filter was developed to cover 120–170 GHz, using microstrip parallelcoupled lines to achieve the desired filter bandwidth, and ensure that the unwanted W-band local oscillator signal would be sufficiently suppressed.