Ultra-low-noise Amplifier for Cryocooled SATCOM Receiver

HYPRES proposes to design, build, deliver and demonstrate a cryocooled digital-RF receiver for reception of the satellite communication X-band (7.25–7.75 GHz). This would be the most advanced in the family of such products developed during the last three years. The cryocooled receiver integrates a low-noise amplifier (LNA) with 5 K noise temperature with a 30 Gsample/s wideband analog-to-digital converter (ADC). The LNA and the ADC will use InP high-electron-mobility transistor (HEMT) and Nb Josephson junction (JJ) large-scale integrated circuit technologies respectively. In addition to the oversampling bandpass delta-sigma ADC, the superconductor chip will include digital in-phase and quadrature downconverters, decimation filters, and improved output drivers. In Phase I, HYPRES collaborated with University of California, Berkeley (UCB) to characterize the LNA gain, linearity and noise temperature over 4–80 K, and investigated SATCOM system architectures for both small and large platforms. Using a modular design with flexible temperature control on a commercial, multi-stage cryogen-free refrigerator, we will evaluate the overall receiver noise figure and validate the expected 1.8–2.5 dB figure-of-merit (G/T) enhancement for both architectures. HYPRES and UCB will continue LNA development, focusing on a novel JJ traveling wave parametric amplifier with lower noise and much lower power dissipation.