Browsing by Author "Kaufel, Gudrun"

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    10 Gb/s monolithic integrated MSM-photodiode AlGaAs/GaAs-HEMT optoelectronic receiver
    (1991) Hurm, Volker; Rosenzweig, Josef; Ludwig, Manfred; Benz, Willi; Osorio, Ricardo; Berroth, Manfred; Hülsmann, Axel; Kaufel, Gudrun; Köhler, Klaus; Raynor, Brian; Schneider, Joachim
    A photoreceiver based on a metal-semiconductor-metal (MSM) photodiode and AlGaAs/GaAs HEMTs is presented. The photoreceiver was fabricated using a 0.5-μm recessed-gate process for double delta-doped quantum-well HEMTs. The following mean values for the enhancement and depletion HEMT parameters, respectively, have been obtained: threshold voltages of 0.1 and -0.5 V, transconductances of 500 and 390 mS/mm, source resistances of 0.7 and 0.6 Ω-mm, and transit frequencies of 35 and 30 GHz. This process includes photodiodes. A deep wet etch was used to deposit the photodiodes on an undoped GaAs buffer layer.
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    10 Gbit/s monolithic integrated Msm-photodiode AlGaAs/GaAs-HEMT optoelectronic receiver
    (1991) Hurm, Volker; Rosenzweig, Josef; Ludwig, Manfred; Benz, Willi; Osorio, Ricardo; Berroth, Manfred; Hülsmann, Axel; Kaufel, Gudrun; Köhler, Klaus; Raynor, Brian; Schneider, Joachim
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    10 Gbit/s monolithic integrated optoelectronic receiver using an MSM photodiode and AlGaAs/GaAs HEMTs
    (1991) Hurm, Volker; Rosenzweig, Josef; Ludwig, Manfred; Axmann, Albert; Benz, Willi; Berroth, Manfred; Osorio, Ricardo; Hülsmann, Axel; Kaufel, Gudrun; Köhler, Klaus; Raynor, Brian; Schneider, Joachim
    A 10 Gbit/s monolithic integrated optoelectronic receiver has been fabricated with a metal-semiconductor-metal (MSM) photodiode and enhancement/depletion 0.5 μm recessed-gate AlGaAs/GaAs HEMTs. A -3 dB bandwidth of 11.3 GHz has been achieved.
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    10-20 Gbit/s GaAs/AlGaAs HEMT ICs for high speed data links
    (1992) Berroth, Manfred; Hurm, Volker; Lang, Manfred; Ludwig, Manfred; Nowotny, Ulrich; Wang, Zhigong; Wennekers, Peter; Hülsmann, Axel; Kaufel, Gudrun; Köhler, Klaus; Raynor, Brian; Schneider, Joachim
    A set of ICs has been developed for high-speed data links at data rates above 10 Gbit/s. A recessed gate process for double pulse doped quantum well transistors has been used with e-beam written 0.3- μm gates. A 4 bit multiplexer and a laser diode driver for the transmitter as well as a transimpedance amplifier, bit synchronizer, and 4 bit demultiplexer for the receiver have been successfully operated with data rates up to 20 Gbit/s.
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    15 Gbit/s integrated laser diode driver using 0.3 μm gate length quantum well transistors
    (1992) Wang, Zhigong; Berroth, Manfred; Nowotny, Ulrich; Gotzeina, Werner; Hofmann, Peter; Hülsmann, Axel; Kaufel, Gudrun; Köhler, Klaus; Raynor, Brian; Schneider, Joachim
    An integrated laser diode driver was realised using enhancement/depletion 0.3 μm recessed-gate AlGaAs/GaAs quantum well transistors. Fully-open eye diagrams were observed at bit rates up to 10 Gbit/s with 50 Ω loads. The maximum DC and modulation current were 25 and 45 mA, respectively. The power consumption is less than 450 mW.
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    16 x 16 bit parallel multiplier based on 6 K gate array with 0.3 μm AlGaAs/GaAs quantum well transistors
    (1992) Thiede, Andreas; Berroth, Manfred; Hurm, Volker; Nowotny, Ulrich; Seibel, Jörg; Gotzeina, W.; Sedler, Martin; Raynor, Brian; Köhler, Klaus; Hofmann, Peter; Hülsmann, Axel; Kaufel, Gudrun; Schneider, Joachim
    The design and performance of a 16x16 bit parallel multiplier based on a 6 K gate array will be presented. This LSI semicustom IC demonstrates the high potential of the authors' AlGaAs/GaAs quantum well FETs with a gate length of 0.3 μm. The best multiplication time measured was 7.2 ns.
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    A 2.5 ns 8 x 8-b parallel multiplier using 0.5 μm GaAs/GaAlAs heterostructure field effect transistors
    (1991) Berroth, Manfred; Hurm, Volker; Nowotny, Ulrich; Hülsmann, Axel; Kaufel, Gudrun; Köhler, Klaus; Raynor, Brian; Schneider, Joachim
    To increase performance of GaAs LSI digital circuits, a 0.5 μm recessed gate process has been developed and utilized for an 8x8-b parallel multiplier. The chip contains about 3000 heterostructure field effect transistors and has a power consumption of 1.5 W. The best results of the maximum multiplication time measured were below 2.5 nsec.
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    20 Gbit/s 2:1 multiplexer using 0.3 μm gate length double pulse doped quantum well GaAs/AlGaAs transistors
    (1991) Nowotny, Ulrich; Lang, Manfred; Berroth, Manfred; Hurm, Volker; Hülsmann, Axel; Kaufel, Gudrun; Köhler, Klaus; Raynor, Brian; Schneider, Joachim
    A high speed 2:1 multiplexer circuit in source coupled FET logic has been developed and fabricated using a recessed gate process for enhancement and depletion transistors with 0.3μm gate length. First results show a data rate of over 20 Gbit/s at 5 V supply voltage and 250 mW power consumption. The output voltage swing is adjustable between 0.3 V and 0.8 V for a 50 Ohm load. The out-put level can be varied between +1 V an -1 V. Comparison between simulation and measurement shows very good agreement.
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    8.2 GHz bandwidth monolithic integrated optoelectronic receiver using MSM photodiode and 0.5 μm recessed-gate AlGaAs/GaAs HEMTs
    (1991) Hurm, Volker; Rosenzweig, Josef; Ludwig, Manfred; Benz, Willi; Berroth, Manfred; Hülsmann, Axel; Kaufel, Gudrun; Köhler, Klaus; Raynor, Brian; Schneider, Joachim
    An 8.2 GHz bandwidth monolithic optoelectronic receiver consisting of an MSM photodiode, a transimpedance amplifier, and a 50 Omega output buffer has been fabricated using an enhancement/depletion 0.5 μm recessed-gate AlGaAs/GaAs HEMT process. Successful operation at data rates up to 10 Gbit/s has been demonstrated.
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    Indirect optically controlled pseudomorphic HEMT based MMIC oscillator
    (1992) Bangert, Axel; Benz, Willi; Berroth, Manfred; Hülsmann, Axel; Hurm, Volker; Kaufel, Gudrun; Köhler, Klaus; Rosenzweig, Josef; Schneider, Joachim
    For the first time an indirect optically controlled monolithic integrated oscillator was fabricated and examined experimentally. The oscillator was designed for a frequency of about 7 GHz. By illuminating a 60x60 μm2 photodiode by the light of a pigtailed laser diode (λ=840 nm), the free-running frequency of the oscillator was tunable in a range of more than 7 MHz. A locking range of more than 3 MHz was achieved. A phase shift in the output signal of nearly 180° has been observed.