Low noise amplifier modules from 220–270 GHz

We present the design and performance of low noise amplifier modules in the WR3 frequency band (220-325 GHz). E-plane split waveguide blocks are used with 25 μm gallium arsenide membrane radial probes to couple signal into and out of 35 nm gate length indium phosphide monolithic millimeter-wave integrated circuit (MMIC) amplifiers. Design, fabrication and testing of the probe transitions and amplifier modules are discussed. For a cascode amplifier module cryogenically cooled to 20 K, we measure a minimum noise temperature of 120 K at 258 GHz and noise temperatures less than 145 K between 234-268 GHz. To our knowledge, these results are the lowest LNA noise temperatures at these frequencies reported to date.