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ABSTRACT: A high efficiency digital MMIC amplifier for mobile communication switch-mode concepts was designed by utilizing a 0.25 mum GaN HEMT technology with f<sub>tau</sub> 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 an output power of 4.4 W for a band pass delta-sigma (BPDS) class-S input signal at a bit rate of 3.6 Gbps equivalent to a 0.9 GHz fundamental was obtained. For the first time the operating mode up to 8 Gbps (2 GHz) is shown with an efficiency of 62%, demonstrating the prospect of future use of GaN HEMTs for switch mode amplifier concepts.
Compound Semiconductor Integrated Circuit Symposium, 2009. CISC 2009. Annual IEEE; 11/2009
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ABSTRACT: Based on a 100 nm metamorphic HEMT process with 220 GHz transit frequency, f<sub>T</sub>, an optimised dynamic 2:1 frequency divider has been designed. The implemented symmetrical design and optimised three-metal interconnect technology with a BCB dielectric layer result in a very small core size which leads to a maximum operation frequency of 108 GHz.
Electronics Letters 07/2003; · 0.96 Impact Factor
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V. Hurm,
W. Bronner, W. Benz,
K. Kohler,
J.-R. Kropp,
R. Losch,
M. Ludwig,
G. Mann,
M. Mikulla,
J. Rosenzweig,
M. Schlechtweg,
M. Walther,
G. Weimann
[show abstract]
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ABSTRACT: A 1 × 12 metal-semiconductor-metal (MSM) photodiode array
operating at 10 Gbit/s per channel was developed for short-haul 0.85
μm wavelength parallel optical links. The GaAs-based MSM photodiodes
with a diameter of 80 μm have a responsivity of 0.30 A/W at 3 V, a
dark current of less than 1 nA at 3 V, a capacitance of 0.20 pF at 1
MHz, and a -3 dB bandwidth of 10 GHz at (2.5 V, 50 Ω)
Electronics Letters 09/2002; · 0.96 Impact Factor
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ABSTRACT: A static frequency divider with a maximum operating frequency of
up to 66 GHz was developed for applications in high-speed digital
systems. To the authors' knowledge, this is the highest operation
frequency obtained for a static divider based on high electron mobility
transistor (HEMT) technology. The complete circuit has a power
consumption of 450 mW at supply voltages V<sub>cc</sub>=2 V and V<sub>ss
</sub>=-3 V. The input signal is single-ended. The differential output
driver is designed in current mode logic (CML) and is able to drive a 50
Ω external load
Electronics Letters 08/2002; · 0.96 Impact Factor
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ABSTRACT: The design and performance of a dynamic divider by four based on a
100 nm metamorphic enhancement HEMT technology operating in the range 58
to 82 GHz is presented. To the knowledge of the authors, this is the
highest operation frequency obtained for a dynamic divider based on HEMT
technology. The complete circuit has a power consumption of
approximately 500 mW for a supply voltage of -3.5 V The input signal is
single-ended. The output driver is able to drive a 50 Ω external
load
Electronics Letters 05/2002; · 0.96 Impact Factor
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ABSTRACT: A novel optoelectronic receiver chip for a data rate of 2.5 Gbit/s
has been developed and tested. It integrates a metal-semiconductor-metal
photodiode with a GaAs transimpedance amplifier, a high gain amplifier
and a limiting output buffer which is able to drive a 50 Ω load. A
special feature of the chip is that it comprises a very large photodiode
of 300 μm diameter, eliminating the need for expensive fibre
alignment. Measurements reveal that the receiver achieves the required
sensitivity of -15.7 dBm at a bit error rate of 10<sup>9</sup>
Electronics Letters 10/2001; · 0.96 Impact Factor
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V. Hurm,
A. Leven, W. Benz,
M. Berking,
W. Bronner,
A. Hulsmann,
K. Kohler,
M. Ludwig,
H. Massler,
J. Rosenzweig,
M. Schlechtweg,
J. Sohn,
H. Walcher,
G. Weimann
[show abstract]
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ABSTRACT: 40 Gbit/s 1.55 μm photoreceivers were manufactured using
GaAs-based HEMT distributed amplifiers. The photoreceivers include
either a integrated surface-illuminated PIN or a flip-chip mounted
edge-illuminated multimode waveguide photodiode
Lasers and Electro-Optics Society 2000 Annual Meeting. LEOS 2000. 13th Annual Meeting. IEEE; 02/2000
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ABSTRACT: Electrical polarisation mode dispersion (PMD) and receiver
bandwidth generated intersymbol interference (ISI) mitigation using an
analogue decision feedback loop for 10 Gbit/s NRZ signals is
demonstrated. ISI caused by first-order (PMD) of up to 120 ps
differential group delay was equalised. Error free recovery of signals
with completely closed eye diagrams was achieved
Electronics Letters 12/1999; · 0.96 Impact Factor
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V. Hurm, W. Benz,
W. Bronner,
A. Hulsmann,
T. Jakobus,
K. Kohler,
A. Leven,
M. Ludwig,
B. Raynor,
J. Rosenzweig,
M. Schlechtweg,
A. Thiede
[show abstract]
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ABSTRACT: A 36.5 GHz bandwidth, 1.55 μm wavelength pin-HEMT photoreceiver
with a distributed amplifier has been monolithically integrated on a 3
in GaAs substrate using a 0.15 μm gate-length pseudomorphic HEMT
process. The pin photodiode has a responsivity of 0.34 A/W.
Clearly-opened eye diagrams for a 40 Gbit/s optical data stream have
been demonstrated
Electronics Letters 11/1998; · 0.96 Impact Factor
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V. Hurm, W. Benz,
W. Bronner,
A. Hulsmann,
T. Jakobus,
K. Kohler,
A. Leven,
M. Ludwig,
B. Raynor,
J. Rosenzweig,
M. Schlechtweg,
A. Thiede
[show abstract]
[hide abstract]
ABSTRACT: A 36.5 GHz bandwidth 1.55 μm wavelength PIN-HEMT photoreceiver
with a distributed amplifier has been monolithically integrated on a
3-inch GaAs substrate. The PIN photodiode has a responsivity of 0.34
A/W. Clearly-opened eye diagrams for a 40 Gbit/s optical data stream
have been demonstrated
Optical Communication, 1998. 24th European Conference on; 10/1998
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R. Kiefer,
R. Losch,
H. Walcher,
M. Walther,
S. Weisser,
K. Czotscher, W. Benz,
J. Rosenzweig,
N. Herres,
M. Maier,
C. Manz,
W. Pletschen,
J. Braunstein,
G. Weimann
[show abstract]
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ABSTRACT: We describe the realization of 1.55 μm InGaAs/InAlGaAs MQW
ridge waveguide laser diodes with InP cladding layers grown by molecular
beam epitaxy with solid sources (SSMBE) and valved cracker cells for
phosphorus and arsenic. For lasers with 10 QWs, a threshold current
density per quantum well of 150 Acm<sup>-2</sup> was extrapolated for
infinitely long cavities. 4×200 μm<sup>2</sup> devices exhibit
a T<sub>0</sub>-value of 85 K in the temperature range from 20 to
85°C and showed a maximum 3 dB modulation bandwidth of 16.5 GHz,
capable of 20 Gbit/s NRZ large signal modulation with an extinction
ratio of 6 dB. These results compare well with MQW lasers grown by MOCVD
Indium Phosphide and Related Materials, 1998 International Conference on; 06/1998
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V. Hurm, W. Benz,
W. Bronner,
T. Fink,
T. Jakobus,
G. Kaufel,
K. Kohler,
Z. Lao,
A. Leven,
M. Ludwig,
C. Moglestue,
B. Raynor,
J. Rosenzweig,
M. Schlechtweg,
A. Thiede,
S. Weisser
[show abstract]
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ABSTRACT: 1.3-1.55 μm 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</sub>Ga<sub>0.47</sub>As MSM and PIN photodiodes grown on
GaAs have nearly identical characteristics to photodiodes grown on InP
Gallium Arsenide Integrated Circuit (GaAs IC) Symposium, 1997. Technical Digest 1997., 19th Annual; 11/1997
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V. Hurm, W. Benz,
W. Bronner,
M. Dammann,
T. Jakobus,
G. Kaufel,
K. Kohler,
Z. Lao,
M. Ludwig,
B. Raynor,
J. Rosenzweig,
M. Schlechtweg
[show abstract]
[hide abstract]
ABSTRACT: The first long wavelength pin-HEMT photoreceiver grown on GaAs has
been manufactured using a 0.3 μm gate length AlGaAs-GaAs HEMT
process. At a wavelength of 1.55 μm the monolithically integrated
InGaAs pin photodiode has responsivity of 0.40 A/W, and the
photoreceiver has a -3 dB bandwidth of 6.9 GHz. Clear and open eye
diagrams for a 10 Gbit/s 1.55 μm optical data stream have been
demonstrated
Electronics Letters 10/1997; · 0.96 Impact Factor
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ABSTRACT: A monolithic integrated optoelectronic receiver for a wavelength
of 1.55 μm consisting of a GaInAs PIN diode and a transimpedance
AlGaAs/GaAs HEMT amplifier has been fabricated. The available technology
includes three etch processes, five metal lift-off processes, an oxygen
implantation for device isolation, two dielectric layers of SiN and an
electroplated gold interconnection layer. The gate levels for
enhancement and depletion FETs were carried out using e-beam lithography
with gate lengths of 0.3 μm. The responsivity of the photodiodes is
0.40 A/W, and the photoreceiver has a -3 dB bandwidth of 6.9 GHz. Clear
and open eye diagrams for a 10 Gbit/s optical data stream have been
obtained. At this data rate the sensitivity of the photoreceiver is
better than -17.5 dBm (BER=10<sup>-9</sup>). The yield of this circuit
is better than 80% realized on 2'' wafers
Compound Semiconductors, 1997 IEEE International Symposium on; 10/1997
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ABSTRACT: Short-haul fiber-optic communication systems require high-speed semiconductor lasers that can operate uncooled over a wide temperature range. In this letter, we describe high-speed short-cavity InGaAs-GaAs multiple-quantum-well lasers operating at 1.1-/spl mu/m wavelength. The Fabry-Perot lasers were fabricated in a triple-mesa geometry suitable for on-wafer probing. With 3/spl times/200 /spl mu/m/sup 2/ ridge-waveguide lasers, which showed the best compromise between high-temperature and high-speed performance, a 3-dB modulation bandwidth of 14.5 GHz at 130/spl deg/C was achieved. Uncooled 20-Gb/s operation of these lasers is presented over a wide-temperature range from 25/spl deg/C to 130/spl deg/C without automatic power control.
IEEE Photonics Technology Letters 06/1997; · 2.19 Impact Factor
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ABSTRACT: We study the influence of lateral carrier diffusion on the properties of In <sub> 0.35 </sub> Ga <sub> 0.65 </sub> As/GaAs multiple quantum well lasers by comparing theoretical and experimental results. A model including the carrier diffusion terms into the rate equations has been used to calculate the dc and small-signal lateral profiles for both unconfined and confined carriers in mesa waveguide devices. The theoretical results were compared with experimental results of the frequency dependence of the subthreshold electrical impedance and small-signal spontaneous emission, and with the measured threshold currents for lasers with different mesa widths. The comparison yielded an estimation for the nonradiative and radiative recombination coefficients, the ambipolar diffusion constant, and the external surface recombination velocity. © 1997 American Institute of Physics.
Journal of Applied Physics 06/1997; · 2.17 Impact Factor
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V. Hurm, W. Benz,
W. Bronner,
T. Fink,
G. Kaufel,
K. Kohler,
Z. Lao,
M. Ludwig,
B. Raynor,
J. Rosenzweig,
M. Schlechtweg,
J. Windscheif
[show abstract]
[hide abstract]
ABSTRACT: The first 20 Gbit/s 1.3-1.55 μm wavelength monolithic
integrated photoreceiver grown on GaAs substrate has been fabricated
using AlGaAs/GaAs HEMTs. At a wavelength of 1.3 μm, the integrated
InGaAs MSM photodiode has a responsivity of 0.32A/W and the
photoreceiver has a -3 dB bandwidth of 16.5 GHz. Clearly-opened eye
diagrams for a 20 Gbit/s 1.55 μm optical data stream have been
demonstrated
Electronics Letters 04/1997; · 0.96 Impact Factor
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ABSTRACT: We have fabricated dry-etched mirrors in high-speed InGaAs/GaAs/AlGaAs pseudomorphic multiple quantum well ridge-waveguide
lasers at 60°C and in InGaAs/InP bulk lasers at 5°C using enhanced chemically assisted ion-beam etching (CAIBE) technique.
The technique allows the etching of laser structures with good surface morphology and excellent anisotropy without cold traps
in the etching system. Characteristics of the dry-etched facet lasers match those of cleaved devices. The low sample temperatures
for etching allowed the use of standard photoresists as etch masks.
Journal of Electronic Materials 08/1996; 25(9):1446-1450. · 1.47 Impact Factor
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S. Weisser,
E.C. Larkins,
K. Czotscher, W. Benz,
J. Daleiden,
I. Esquivias,
J. Fleissner,
J.D. Ralston,
B. Romero,
R.E. Sah,
A. Schonfelder,
J. Rosenzweig
[show abstract]
[hide abstract]
ABSTRACT: We demonstrate record direct modulation bandwidths from MBE-grown In/sub 0.35/Ga/sub 0.65/As-GaAs multiple-quantum-well lasers with undoped active regions and with the upper and lower cladding layers grown at different growth temperatures. Short-cavity ridge waveguide lasers achieve CW direct modulation bandwidths up to 40 GHz for 6/spl times/130 /spl mu/m/sup 2/ devices at a bias current of 155 mA, which is the damping limit for this structure. We further demonstrate large-signal digital modulation up to 20 Gb/s (limited by the measurement setup) and linewidth enhancement factors of 1.4 at the lasing wavelength at threshold of /spl sim/1.1 /spl mu/m for these devices.
IEEE Photonics Technology Letters 06/1996; · 2.19 Impact Factor
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ABSTRACT: The first 10 Gbit/s 1.3-1.55 μm wavelength monolithic
integrated photoreceiver grown on GaAs substrate has been fabricated
using a 0.3 μm gate length AlGaAs-GaAs HEMT process. At a wavelength
of 1.3 μm the integrated InGaAs MSM photodiode has a DC responsivity
of 0.34 A/W. The photoreceiver bandwidth is 7.1 GHz and its sensitivity
is better than -14.7 dBm (BER=10<sup>-9</sup>)
Indium Phosphide and Related Materials, 1996. IPRM '96., Eighth International Conference on; 05/1996
