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ABSTRACT: The system power amplifier's linearity sets the maximum bit rate and the efficiency determines the maximum output power possible given a fixed heat dissipation or DC supply. This paper demonstrates that using a GaAs PHEMT 0.15μm gate process, industry leading performance can be attained. Shown is a 15GHz linear power amplifier capable of -52dBc IM3 at 21dBm output power (+47dBm OIP3). Also demonstrated is a 30GHz saturated power amplifier capable of making 38dBm (6W) output power at 38% peak power added efficiency. Both are fully matched to 50 Ω and have over 20dB of gain. Both are housed in a low cost laminate surface mount package.
Microwave Integrated Circuits Conference (EuMIC), 2010 European; 10/2010
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ABSTRACT: The higher frequency bands of the point-to-point infrastructure radio have been the hardest to convert to SMT package. This paper describes complete solution that covers 37-45GHz in 4 SMT packaged chips. Transmit consist of 2 chips, an up-converter/VGA with 20dB gain control and power amplifier that provides 38dBm OIP3. The receiver is a single chip down-converter with less than 4.9dB NF. The single chip LO buffer provides frequency multiplication (×2) and +21dBm drive with ample harmonic suppression. An optional high directivity, temperature compensated, power detector is also available to aid forward error correction. The result is the most integrated and complete chip set known to be published or advertised.
Microwave Symposium Digest (MTT), 2010 IEEE MTT-S International; 06/2010
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Journal of Gastroenterology and Hepatology 06/2010; 25(7):1329 - 1329. · 2.87 Impact Factor
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ABSTRACT: An optical photo lithography based 0.15 μm GaAs PHEMT process and 2 mil-substrate technology that enables high production throughput and low cost is described. The developed process achieved Imax = 575 mA/mm, BVgd = 14 V, and 753 mW/mm of output power density at P-1 condition at 18 GHz. Design and test results for balanced and single-ended power amplifiers (PA) for 40 to 85 GHz applications are described as process capability verification. Balanced PA MMICs shows 18 dB of small-signal gain and 17 dBm of output power up to 85 GHz frequencies. MMIC test results verified the process capability to manufacture MMIC devices for applications up to 90 GHz.
Microwave Conference, 2009. EuMC 2009. European; 11/2009
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ABSTRACT: While most point-to-point radio systems migrate to SMT(surface mount technology) over chip-and-wire, the 38 GHz band has provided the largest challenge. This paper demonstrates a commercially viable complete SMT solution to receive LNA-down-converter and transmit up-converter, VGA, power amp and directional power detector. The receive chain provides 10 dB conversion gain with 4.5 dB NF. The transmit chain provides 26 dB maximum total gain with 24 dB gain control and 30 dBm maximum power out at 1 dB compression. The amplifiers are housed in 5×5 mm packages while the detector uses a chip scale 1×0.5 mm package. All cover the 37 to 42 GHz radio bands. This is the only known complete SMT Tx/Rx solution to be published or demonstrated.
Microwave Conference, 2009. EuMC 2009. European; 11/2009
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Y. Onishi,
N. Saga,
K. Koyama,
H. Doi,
T. Ishizuka,
T. Yamada, K. Fujii,
H. Mori,
J.-i. Hashimoto,
M. Shimazu,
A. Yamaguchi,
T. Katsuyama
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ABSTRACT: A long-wavelength GaInNAs vertical-cavity surface-emitting laser with a buried tunnel junction (BTJ) has been demonstrated in this paper. It has been shown that a combination of a GaAs-based BTJ for a current confinement, GaInNAs multi-quantum wells for an active region, a dielectric distributed Bragg reflector (DBR) for a top mirror, and an AlGaAs/GaAs DBR for a bottom mirror is desirable to realize high-speed operation at high temperature. The maximum output power of 4.2 mW with a low resistance of 65 Omega has been obtained at 25degC. Operations of 10 Gb/s have been achieved over the temperature range of 25degC-85degC, with operation current of 6.9 mA and extinction ratio of 5.0 dB.
IEEE Journal of Selected Topics in Quantum Electronics 07/2009; · 3.78 Impact Factor
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ABSTRACT: Optical properties of wurtzite ZnO bulk single crystals in which an arbitrary number (typically 10<sup>9</sup>–10<sup>10</sup> cm <sup>-2</sup> ) of fresh dislocations were introduced intentionally by the plastic deformation at elevated temperatures (923–1073 K) were examined. Deformed specimens showed excitonic light emission with photon energies of 3.100 and 3.345 eV, as well as their LO phonon replicas at 11 K. The light intensities increased with increasing dislocation density. The activation energy for a thermal quenching of the 3.100 or 3.345 eV emission band, which corresponds to the depth of the localized energy level associated with the emission band, was estimated to be 0.3±0.1 or 0.05±0.01 eV , respectively. The origin of the energy levels was proposed as point defect complexes involving dislocations. The introduction of the dislocations at the elevated temperatures above 923 K did not influence the intensities of the emission bands except the dislocation-related emission bands.
Journal of Applied Physics 11/2008; · 2.17 Impact Factor
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ABSTRACT: Er-related photoluminescence (PL) properties have been investigated in Er,O-codoped GaAs (GaAs:Er,O) grown by organometallic vapor phase epitaxy. The GaAs:Er,O which was slightly doped with Er exhibited both strong Er-related and band-edge luminescence. In the temperature dependence of the Er-related PL intensity, the intensity decreased with increasing temperature from 4.2 K to 30 K. The temperature region was quite coincident with the region where the Carbon-related PL intensity decreased. This behaviour implies the existence of a Carbon-related nonradiative process in GaAs. (© 2008 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)
physica status solidi (c) 06/2008; 5(9):2864 - 2866.
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M. MIZUNO,
M. MIZOKAMI,
E. ORITO,
K. OHBA, K. FUJII,
K. SUZUKI,
H. TOKUDA,
M. NARITA,
T. OHNO,
M. YAMAUCHI,
Y. HIRASHIMA,
T. NAKANO,
M. OGINO,
M. YAMAMOTO
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ABSTRACT: The hepatitis C virus (HCV) core antibody and NS-4 antibody were measured in 25 cases of type C chronic hepatitis after interferon (IFN) treatment. The antibody titres were quantitated and the changes in the antibody titres and the therapeutic effects were compared. The titres of the passive haemagglutination assay (HCV-PHA) before and after IFN administration were also measured and compared with the therapeutic effects. No significant correlation was seen between the core, NS-4 and HCV-PHA titres before IFN administration and the resultant therapeutic effects, but many cases showing excellent effects were seen among those with core antibody titres under 100 U/L and those with HCV-PHA titres less than 2.16 In a study of the changes in the core and NS-4 antibody titres, these titres tended to decrease during IFN administration. In cases showing excellent effects, these decreases continued for a long period after completion of IFN administration and then became negative in some cases. However, in the remaining cases, titres showed increases up to 3 months after completion of IFN administration. HCV-PHA showed reduced titres in many cases of excellent effects before and after IFN administration; and there were also cases showing decreases with two power differences.
Journal of Gastroenterology and Hepatology 03/2008; 8(S1):S103 - S109. · 2.87 Impact Factor
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ABSTRACT: Vertical light-emitting diodes (LEDs) were successfully fabricated by a chemical lift-off process using a selectively etchable CrN buffer layer. The novel CrN metallic layer worked well as a buffer layer for growth of the GaN LED and was etched out clearly during selective chemical etching. The vertical LED by chemical lift-off showed very good current-voltage performance with low series resistance of 0.65 Omega and low operated voltage of 3.11 V at 350 mA. Also, this device could be operated at a much higher injection forward current (1118 mA at 3.70 V) by thermally conductive metal substrate which enabled the high current operation with excellent heat dissipation.
IEEE Photonics Technology Letters 03/2008; · 2.19 Impact Factor
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ABSTRACT: An arbitrary number of dislocations were freshly introduced in wurtzite ZnO bulk single crystals by plastic deformation at high temperatures (923–1123 K), and the optical properties were examined by photoluminescence spectroscopy. ZnO, including a high density (more than 109 cm−2) of dislocations, showed excitonic light emission with photon energies of 3.100 and 3.345 eV, as well as their LO-phonon replicas, at a temperature of 11 K, and the intensities increased with increasing dislocation density.
Applied Physics Letters 01/2008; 92(1):011922-011922-3. · 3.84 Impact Factor
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ABSTRACT: This paper presents two high dynamic range amplifiers in the 7-21GHz and 18-32 GHz that are easy to use, high performance and low cost. For ease of use they are housed in 5x5 mm surface mount package and integrate 50 Omega input/output matching. In measured results, the 7-21 GHz amplifier delivers over 20 dB gain, 2.3 dB NF, 28 dBm OIP3 and the 18-32 GHz amplifier provides over 20 dB gain, 2.8 dB NF and 28 dBm OIP3. Cost is kept low through utilization of PHEMT 6" wafers and volume automated package panel assembly and test. These products are unique and industry leading in all aspects of design, packaging, performance and cost.
Microwave Conference, 2007. European; 11/2007
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ABSTRACT: A wideband image-rejection distributed resistive mixer configuration has been demonstrated. A 6-30GHz image-rejection mixer has been integrated onto a single GaAs MMIC chip and then packaged into a low cost 5×5mm surface mount (SMT) package. The completed mixer showed -10dB typical conversion gain with 15dB image-rejection ratio over the band.
Microwave Symposium Digest, 2005 IEEE MTT-S International; 07/2005
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Die Makromolekulare Chemie 03/2003; 117(1):275 - 278.
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ABSTRACT: Fluorine magnetic resonance spectra of poly(vinyl trifluoroacetate) samples of different tacticities were investigated, along with those of model compounds. These polymers represent the first case where the line order in respect to stereostructure does not agree with that expected from the spectra of model compounds. More than four peaks were observed for signals from the trifluoromethyl groups of the polymers and the relative peak positions differed from those previously reported. The intensity ratios of the peaks were affected by the solvent employed. Therefore the spectra cannot be interpreted in terms of triad stereosequences. Seemingly longer stereosequences or other influences have to be considered to interpret the spectra.
Journal of Polymer Science Part A-1 Polymer Chemistry 03/2003; 6(8):2387 - 2396.
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ABSTRACT: Development of hierarchical computer complex concept and its application to nuclear power plants is reported. The hierarchical computer complex is an integrated system for control, monitoring, and management of the plant and consists of a large number of computers and processors. The hierarchical computer complex (HCC) has three levels; The first and the uppermost level is for site management purposes, the second level is for unit level plant monitoring systems, and the third and the lowest level is that for local system control. Fast speed dataway linkage is provided between computers and/or controllers at each level and also between different levels for rapid transmission of control and information data.
IEEE Transactions on Nuclear Science 03/1983; · 1.45 Impact Factor
