Michael E. Barsky

Cryogenic wide-band ultra-low-noise IF amplifiers operating at ultra-low DC power

This paper describes cryogenic broad-band amplifiers with very low power consumption and very low noise for the 4-8-GHz frequency range. At room temperature, the two-stage InP-based amplifier has a gain of 27 dB and a noise temperature of 31 K with a power consumption of 14.4 mW per stage, including bias circuitry. When cooled to 15 K, an input noise temperature of 1.4 K is obtained at 5.7 mW per stage. At 0.51 mW per stage, the input noise increases to 2.4 K. The noise measurements have been repeated at different laboratories using different methods and are found consistent.

AlGaN/GaN HEMTs - operation in the K-band and above

Reports on the power and microwave noise performance of AlGaN/GaN high electron-mobility transistors (HEMTs) at frequencies f>18 GHz (K- and Ka-bands). At 20 GHz, a record continuous-wave output power of 1.6 W has been achieved on an eight-finger 500-/spl mu/m total gate-periphery device. At 29 GHz, a 120-/spl mu/m gate-periphery device showed a pulsed output density of 1.6 W/mm with an associated gain of 6.7 dB and power-added efficiency of 26%. Minimum noise figure of 1.5 dB has been achieved on a 0.2 /spl mu/m /spl times/ 200 /spl mu/m device at 26 GHz. The data demonstrate the viability of AlGaN/GaN HEMTs for high-frequency power and low-noise amplifier applications.

Sub-20-K noise temperature LNA for 67–90 GHz frequency band

Indium Phosphide MMIC LNAs are enabling new capabilities in instrument development. The development of arrays of hundreds of cryogenically-cooled millimeter wave receivers has previously been challenging, but is now achievable with highly repeatable MMIC processes and advances in cryogenic on-wafer testing of LNAs. We have developed InP HEMT LNA MMICs for the 67–90 GHz frequency band that is the last missing receiver system from the ALMA. These MMICs provided average performance of less than 22.5 K noise temperature over the frequency band and minimum noise temperature of 17.5 K at 72 GHz. These LNAs achieve NT=220K (NF=2.4dB) at 90 GHz for Earth remote sensing instrument on Sentinel-6. Our HRMR (High Resolution Microwave Radiometer) achieves NEDT < 0.05K enabling Sentinel-6 to measure coastal ocean topography at 3 km resolution with better than 1 cm accuracy.

Enhancement-Mode InGaAs/InAlAs/InP High Electon Mobility Transistor with 0.1 µm Gate

We present state-of-the-art performance of 0.1 µm gate enhancement-mode (E-mode) InGaAs/InAlAs/InP high electron mobility transistors (HEMTs) fabricated on 3-inch wafers in a production environment. The E-mode HEMTs have transconductance of 1180 mS/mm, cutoff frequency of 210 GHz, and less than 1 mA/mm Idss (drain current at a gate bias of zero volts), measured at a drain bias of 1 V. The device characteristics make the E-mode HEMTs suitable candidates for ultra-high-speed analog and digital applications. Enhancement-mode HEMT devices and low noise amplifiers utilizing E-mode HEMTs, which were fabricated on 3-inch wafers in TRWs InP production line, demonstrated excellent repeatability, performance, yield, and uniformity.