— A high efficiency digital MMIC amplifier for mobile communication switch-mode concepts was designed by utilizing a 0.25 μm GaN HEMT technology with f T of 32 GHz. A comparative investigation of two different driver concepts for a 1.2 mm GaN HEMT PA is shown. The MMICs were on-wafer evaluated for class-D and class-S operation. A drain efficiency of 70% for… (More)
This paper describes efficient GaN/AlGaN HEMTs and MMICs for L/S-band (1-4 GHz) and X-band frequencies (8-12 GHz) on three-inch s.i. SiC substrates. Dual-stage MMICs in microstrip transmission-line technology yield a power-added efficiency of ¿40% at 8.56 GHz for a power level of ¿11 W. A single-stage MMIC yields a PAE of ¿55% with 6 W of output power at… (More)
The reliability and degradation mechanism of AlGaN/GaN single stage amplifiers after 10 GHz stress at a drain voltage of 42 V and channel temperatures above 250°C was investigated using electroluminescence (EL) imaging, infrared thermography, and TEM. The extrapolated median lifetime extracted from the Arrhenius plot is 510<sup>5</sup> h at a channel… (More)
Two field plate variants of AlGaN/GaN-HEMTs with and without source-connected field plate (“shield”) were analyzed for the design of efficient High-Power-Amplifier MMICs operating at X-Band frequencies. This paper presents the design and realization of three dual-stage microstrip MMICs using different device variants for narrowband and… (More)
This paper describes a balanced AlGaN/GaN HEMT single-stage power amplifier demonstrator for X-band frequencies in microstrip line technology on thinned s.i. SiC substrates. The design features a modular circuit concept and microstrip MMIC directional couplers with low impedance levels. These 3 dB-couplers designed for a center frequency of 10 GHz show a… (More)
Using our 0.2 /spl mu/m AlGaAs-GaAs-AlGaAs quantum well HEMT technology, we have designed, manufactured and characterized a single chip comprising a clock recovery, a data decision and a 2:4 demultiplexer circuit. The chip is able to receive a data stream of 40 Gbit/s and converts it into a four bit parallel data signal. The results presented here have been… (More)
1.3 - 1.55μm wavelength 20 Gbit/s MSM-HEMT and 10 Gbit/s PIN-HEMT photoreceivers have been monolithically integrated on GaAs substrates using a 0.3 μm gate length AlGaAs/GaAs HEMT process. The In/sub 0.53/Ga/sub 0.47/As MSM and PIN photodiodes grown on GaAs have nearly identical characteristics to photodiodes grown on InP.
Two monolithic integrated transmitter circuits of a modulator driver and a modulator driver with a 2:1 multiplexer for high-speed optical-fiber links are presented. The ICs featuring differential configuration were fabricated in a 0.2 /spl mu/m gate-length enhancement and depletion HEMT technology with 60 GHz and 55 GHz f/sub T/. The modulator driver… (More)