| 1. |
- Egard, Mikael, et al.
(författare)
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Frequency Modulation in mm-Wave InGaAs MOSFET/RTD Wavelet Generators
- 2013
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Ingår i: 2013 International Conference on Indium Phosphide and Related Materials (IPRM). - 1092-8669. ; , s. 1-2
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Konferensbidrag (refereegranskat)abstract
- Co-integration of an InGaAs MOSFET and an RTD is performed to realize a wavelet generator. The large transconductance of the MOSFET (1.9 mS/mu m) is used to switch the current in an oscillator circuit and coherent wavelets down to 41 ps are generated in the frequency domain of 50 to 100 GHz. The lowest power consumption measured is 1.9 pJ/pulse. It is found that the supply bias can be used to modulate the center frequency of the wavelets.
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| 2. |
- Egard, Mikael, et al.
(författare)
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High-Frequency Performance of Self-Aligned Gate-Last Surface Channel In0.53Ga0.47As MOSFET
- 2012
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Ingår i: IEEE Electron Device Letters. - 0741-3106. ; 33:3, s. 369-371
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Tidskriftsartikel (refereegranskat)abstract
- We have developed a self-aligned L-g = 55 nm In-0.53 Ga-0.47 As MOSFET incorporating metal-organic chemical vapor deposition regrown n(++) In0.6Ga0.4As source and drain regions, which enables a record low on-resistance of 199 Omega mu m. The regrowth process includes an InP support layer, which is later removed selectively to the n(++) contact layer. This process forms a high-frequency compatible device using a low-complexity fabrication scheme. We report on high-frequency measurements showing f(max) of 292 GHz and f(t) of 244 GHz. These results are accompanied by modeling of the device, which accounts for the frequency response of gate oxide border traps and impact ionization phenomenon found in narrow band gap FETs. The device also shows a high drive current of 2.0 mA/mu m and a high extrinsic transconductance of 1.9 mS/mu m. These excellent properties are attributed to the use of a gate-last process, which does not include high temperature or dry-etch processes.
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| 3. |
- Egard, Mikael, et al.
(författare)
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High Transconductance Self-Aligned Gate-Last Surface Channel In0.53Ga0.47As MOSFET
- 2011
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Ingår i: 2011 IEEE International Electron Devices Meeting (IEDM). - 9781457705052
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Konferensbidrag (refereegranskat)abstract
- In this paper we present a 55 nm gate length In0.53Ga0.47As MOSFET with extrinsic transconductance of 1.9 mS/mu m and on-resistance of 199 Omega mu m. T he self-aligned MOSFET is formed using metalorganic chemical vapor deposition regrowth of highly doped source and drain access regions. The fabricated 140 nm gate length devices shows a low subthreshold swing of 79 mV/decade, which is attributed to the described low temperature gate-last process scheme.
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| 4. |
- Egard, Mikael, et al.
(författare)
-
In0.53Ga0.47As RTD-MOSFET Millimeter-Wave Wavelet Generator
- 2012
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Ingår i: IEEE Electron Device Letters. - 0741-3106. ; 33:7, s. 970-972
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Tidskriftsartikel (refereegranskat)abstract
- We report on the fabrication of a self-aligned regrown In0.53Ga0.47As metal-oxide-semiconductor field-effect transistor (MOSFET) and a resonant tunneling diode (RTD). The performance of these devices is demonstrated by integrating them in parallel with an inductive coplanar waveguide stub to form a highly energy-efficient 70-GHz wavelet generator. The fast switching and low on-resistance of the MOSFET make it possible to kick-start and rapidly quench this RTD-driven oscillator circuit, which produces 41-ps-short wavelets at 15 Gpulses/s, a peak output power of 7 dBm, and an energy consumption of 1.9 pJ/pulse.
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| 5. |
- Jacobsson, Josefin A., et al.
(författare)
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Detailed Analysis of Variants in FTO in Association with Body Composition in a Cohort of 70-Year-Olds Suggests a Weakened Effect among Elderly
- 2011
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Ingår i: PLOS ONE. - : Public Library of Science (PLoS). - 1932-6203. ; 6:5, s. e20158-
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Tidskriftsartikel (refereegranskat)abstract
- Background: The rs9939609 single-nucleotide polymorphism (SNP) in the fat mass and obesity (FTO) gene has previously been associated with higher BMI levels in children and young adults. In contrast, this association was not found in elderly men. BMI is a measure of overweight in relation to the individuals' height, but offers no insight into the regional body fat composition or distribution. Objective: To examine whether the FTO gene is associated with overweight and body composition-related phenotypes rather than BMI, we measured waist circumference, total fat mass, trunk fat mass, leg fat mass, visceral and subcutaneous adipose tissue, and daily energy intake in 985 humans (493 women) at the age of 70 years. In total, 733 SNPs located in the FTO gene were genotyped in order to examine whether rs9939609 alone or the other SNPs, or their combinations, are linked to obesity-related measures in elderly humans. Design: Cross-sectional analysis of the Prospective Investigation of the Vasculature in Uppsala Seniors (PIVUS) cohort. Results: Neither a single SNP, such as rs9939609, nor a SNP combination was significantly linked to overweight, body composition-related measures, or daily energy intake in elderly humans. Of note, these observations hold both among men and women. Conclusions: Due to the diversity of measurements included in the study, our findings strengthen the view that the effect of FTO on body composition appears to be less profound in later life compared to younger ages and that this is seemingly independent of gender.
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| 6. |
- Ohlsson, Lars, et al.
(författare)
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Admittance Matching of 60 GHz Rectangular Dielectric Resonator Antennas for Integrated Impulse Radio
- 2010
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Ingår i: [Host publication title missing]. ; , s. 253-256
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Konferensbidrag (refereegranskat)abstract
- Methods to achieve admittance matching of rectangular dielectric resonator antennas intended for 60~GHz impulse radio are reported. The motivation is to find a suitable antenna that may be integrated in the V-band gated tunnel diode wavelet generator, replacing its tank circuit and forming a low complexity transmitter. Probed one- and two-port scattering parameter measurements have been performed to characterise the fabricated antennas. Changing the feed structure from a tapered dipole to an offset fed and tapered slot, a change from capacitive to inductive characteristics is observed, and the matching to the gated tunnel diode is improved. Deembedded admittance resonance frequencies of fabricated antennas were found at 53.6 and 52.2~GHz for dipole and slot fed antennas, respectively. Characterising the transmission link between dipole fed antennas, a maximum antenna gain of 10.5~dBi and a 3~dB power bandwidth of 1.5~GHz were found at 53.3~GHz.
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| 7. |
- Roll, Guntrade, et al.
(författare)
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RF and DC Analysis of Stressed InGaAs MOSFETs
- 2014
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Ingår i: IEEE Electron Device Letters. - 0741-3106. ; 35:2, s. 181-183
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Tidskriftsartikel (populärvet., debatt m.m.)abstract
- A complete reliability study of the DC and RF characteristics for InGaAs nMOSFETs with aluminium oxide/ hafnium oxide dielectric is presented. The main stress variation at high frequencies is related to a threshold voltage shift, whereas no decrease is found in the maximum of the cut-off frequency and RF-transconductance. Constant gate stress leads to a charge build up causing a threshold voltage shift. Furthermore, electron trapping at the drain side degrades the performance after hot carrier stress. The maximum DC-transconductance is reduced following constant gate bias stress, by an increase in charge trapping at border defects. These border defects at the channel/high-k interface are filled by cold carrier trapping when the transistor is turned on, whereas they do not respond at high frequencies.
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| 8. |
- Wernersson, Lars-Erik, et al.
(författare)
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III-V Nanowires-Extending a Narrowing Road
- 2010
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Ingår i: Proceedings of the IEEE. - 0018-9219. ; 98:12, s. 2047-2060
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Tidskriftsartikel (refereegranskat)abstract
- Semiconductor nanowires have attracted considerable attention during the last decade and are considered as an alternative path to extend the road for scaled semiconductor devices. The interest is motivated by the improved electrostatic control in the cylindrical geometry and the possibility to utilize heterostructures in transistor design. Currently, nanowire transistors have been realized both in III-Vs and in group IV materials employing top-down as well as bottom-up technologies. In this review, we give an overview of the field and, in particular, we summarize state-of-the-art for III-V nanowire devices. It is demonstrated that the growth and processing technologies are maturing and that devices with good transistor characteristics are being fabricated by a combined bottom-up and top-down approach. Also, the first radio-frequency (RF)-implementations are reviewed and discussed.
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| 9. |
- Ärlelid, Mats, et al.
(författare)
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60 GHz impulse radio measurements
- 2011
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Ingår i: 2011 IEEE International Conference on Ultra-Wideband (ICUWB). - 2162-6588. - 9781457717635 ; , s. 536-540
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Konferensbidrag (refereegranskat)abstract
- The bit-error rate of a 60 GHz wireless impulse radio link is investigated at a bit-rate of 4 Gbps using on-off keying. The measurement results show that it is possible to have a BER below 10(-12), and the measured BER vs. E-b/N-o is approximately 1 dB from the theoretical value. The reliability of the wideband 60 GHz wavelet generator is furthermore confirmed by studying the number of faulty wavelets generated, and the circuit performance is characterized. The wavelet generator consumes 30 mW and may generate signals with bandwidth exceeding 25 GHz, which may be used to investigate the channel properties at 60 GHz.
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| 10. |
- Ärlelid, Mats, et al.
(författare)
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Impulse-based 4 Gbit/s radio link at 60 GHz
- 2011
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Ingår i: Electronics Letters. - : Institution of Engineering and Technology (IET). - 1350-911X .- 0013-5194. ; 47:7, s. 70-467
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Tidskriftsartikel (refereegranskat)abstract
- A 4 Gbit/s radio link using impulse-based on-off keying at 60 GHz is demonstrated. The input baseband signals are transferred to radio frequency wavelets through direct conversion, by switching a GaAs gated tunnel diode oscillator on and off. The wavelet generator drives an antenna directly without any buffer or power amplifier. The peak output power is - 11 dBm at a power consumption of 30 mW. The signals are detected with an energy detector and the link has a bit error rate < 10(-12) for distances shorter than 35 cm.
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