Noise Canceling Rad Hard Extremely High Frequency (EHF) Low Noise Amplifier

ABSTRACT: Low Noise Amplifiers covering the 20.2 to 21.2 GHz band with ultra-low noise figures of less than 0.45 dB at the MMIC level and 0.65 dB at the module"s waveguide flange or coaxial level are proposed. This represents a reduction of nominally 0.5 dB over available LNAs. There is a need for front-end components to exploit the increasingly crowded K-band spectrum for both space and terrestrial government and commercial communications links. Recent noise-cancelling methodologies for multi-octave bandwidth amplifiers where the common-gate noise of a common-gate/common-source input is cancelled will be investigated as a means of further reducing the noise figure and/or improving the bandwidth. The baseline approach, for comparison, will use reactively-matched methodologies with common-source input. The proposed baseline technology for all circuits, 50 nm InP MHEMTs grown on GaAs, shows the lowest noise and highest gain in K-band. The linearity, power consumption, gain, and dynamic range will be investigated. Gating criteria include operation over -40 oC to + 80 oC and a path to space-qualification. Applicability of the noise-cancelling approach to full-waveguide-bandwidth (~40%) coverage, and linearization techniques will be investigated BENEFIT: The proposed ultra-low noise amplifiers will enable efficient use of the K-band frequencies in receiving QAM and QPSK with high linearity. Government and military applications include satellite downlink and uplink reception of spectrally efficient waveforms, Satcom-On-The-Go, satellite-to-satellite links, full-waveguide bandwidth weather and ice-coverage observation, radio astronomy (low-power consumption cooled LNAs), battlefield communications, and secure communications. Dual-use applications include commercial Satcom fixed and mobile reception. The technology is transferrable to communications applications in general.