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— 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)
Using our 0.2 pm AlGaAs-GaAs-AlGaAs quantum well HEMT technology, we have designed a chip set for 20-40 Gbit/s transmission systems. In this paper we describe five chips for the receiver side. The presented results have been measured on wafer.
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 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)
A single-chip frequency synthesizer using a 0.3 micron enhancement-depletion HEMT-process is presented. The circuit is a prototype for the local oscillator source of future low cost millimeter wave systems, such as intelligent cruise control radars (76 GHz) or very high speed wireless LANs (60 GHz). It integrates all the components needed to generate a… (More)