| 1. |
- Andersson, Kristoffer, 1976, et al.
(författare)
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Fabrication and characterization of field-plated buried-gate SiC MESFETs
- 2006
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Ingår i: IEEE Electron Device Letters. - 0741-3106 .- 1558-0563. ; 27:7, s. 573-575
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Tidskriftsartikel (refereegranskat)abstract
- Silicon carbide (SiC) MESFETs were fabricated using a standard SiC MESFET structure with the application of the "buried-channel" and field-plate (FP) techniques in the process. FPs combined with a buried-gate are shown to be favorable concerning output power density and power-added efficiency (PAE), due to higher breakdown voltage and decreased output conductance. A very high power density of 7.8 W/mm was measured on-wafer at 3 GHz for a two-finger 400-/spl mu/m gate periphery SiC MESFET. The PAE for this device was 70% at class AB bias. Two-tone measurements at 3 GHz /spl plusmn/ 100 kHz indicate an optimum FP length for high linearity operation.
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| 2. |
- Nilsson, Per-Åke, 1964, et al.
(författare)
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Influence of Field Plates and Surface Traps on Microwave Silicon Carbide MESFETs
- 2008
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Ingår i: IEEE Transactions on Electron Devices. - 1557-9646 .- 0018-9383. ; 55:8, s. 1875-1879
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Tidskriftsartikel (refereegranskat)abstract
- The influence of field plates and surface traps on silicon carbide MESFETs for microwave operation was investigated. By increasing the length of gate-connected field plates from 50 to 800 nm, it was possible to increase the gate–drain breakdown voltage of the devices from 125 to 170 V. At the same time, the current slump effect of traps in the passivation oxide was reduced. By using a combination of field plates and a passivation oxide with low interface trap density, it was possible to reach an output power density of 8 W/mm at 3 GHz.
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| 3. |
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| 4. |
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| 5. |
- Sudow, Mattias, 1980, et al.
(författare)
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The Chalmers microstrip SiC MMIC Process
- 2005
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Ingår i: Conference Proceedings Gighahertz 2005.
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Konferensbidrag (refereegranskat)abstract
- A generic microstrip MMIC process targeted for SiC and GaN technology has beendeveloped. Passive components for high power operation were developed and verified. Circuit modelsfor both passive and active components have been formulated. Using the developed MMIC process anamplifier and a limiter have been manufactured.
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| 6. |
- Cha, Eunjung, 1985, et al.
(författare)
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Cryogenic low-noise InP HEMTs: A source-drain distance study
- 2016
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Ingår i: 2016 Compound Semiconductor Week, CSW 2016. - 9781509019649 ; , s. Article number 7528576-
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Konferensbidrag (refereegranskat)abstract
- The scaling effect of the source-drain distance was investigated in order to improve the performance of low-noise InP HEMTs at cryogenic temperatures 4-15 K. The highest dc transconductance at an operating temperature of 4.8 K and low bias power was achieved at a source-drain distance of 1.4 mu m. The extracted HEMT minimum noise temperature was 0.9 K at 5.8 GHz for a 3-stage 4-8 GHz hybrid low-noise amplifier at 10 K.
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| 7. |
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| 8. |
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| 9. |
- Gudjonsson, Gudjon, 1973, et al.
(författare)
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Design and Fabrication of 4H-SiC RF MOSFETs
- 2007
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Ingår i: IEEE Transactions on Electron Devices. - 1557-9646 .- 0018-9383. ; 54:12, s. 3138-3145
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Tidskriftsartikel (refereegranskat)abstract
- We present simulations, fabrication and analysis of 4H-SiC RF power MOSFETs. We obtain an extrinsic transition frequency of 11.2 GHz and an f max = 11.9 GHz, a breakdown voltage above 200 V and an output power of 1.9 W/mm at 3 GHz. The measured devices are double fingered, source-gate-draingate-source with 2 × 0.4 mm total gate width and the nominal channel length of the devices is 0.5 μm. To the authors knowledge, this is the highest transition frequency and output power density ever reported for SiC RF MOSFETs. The antipunchthrough is introduced as a way to take advantage of the SiC's material properties. A detailed description of the device processing is also given. © 2007 IEEE.
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| 10. |
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| 11. |
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| 12. |
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| 13. |
- Gudjonsson, Gudjon, 1973, et al.
(författare)
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High Frequency 4H-SiC MOSFETs
- 2007
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Ingår i: Materials Science Forum. - 1662-9752 .- 0255-5476. ; 556-557, s. 795-798
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Konferensbidrag (refereegranskat)
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| 14. |
- Gudjonsson, Gudjon, 1973, et al.
(författare)
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High Power Density 4H-SiC RF MOSFETs
- 2006
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Ingår i: IEEE Electron Device Letters. ; 527-529, s. 1277-1280
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Tidskriftsartikel (refereegranskat)
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| 15. |
- Hjelmgren, Hans, 1960, et al.
(författare)
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Electro-thermal simulations of a microwave 4H-SiC MESFET on high purity semi-insulating substrate
- 2007
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Ingår i: Solid-State Electronics. - : Elsevier BV. - 0038-1101. ; 51:8, s. 1144-1152
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Tidskriftsartikel (refereegranskat)abstract
- DC and small-signal electro-thermal simulations of a 4H-SiC microwave power MESFET on a high purity semi-insulating substrate are compared to measurements. The focus is on the electron transport, substrate traps, and thermal heating. The doping concentrations are described by measured SIMS profiles, and the material parameters are in accordance with published results. Although the simulated MESFET has a p-buffer and a high purity substrate, the simulations show that the density of shallow traps affects the device characteristics.The very good agreement between simulated and measured DC and small-signal characteristics indicates that the models for electron mobility, substrate traps, and heating are the most important to achieve good agreement with measured data.
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| 16. |
- Hjelmgren, Hans, 1960, et al.
(författare)
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Transient Simulation of Microwave SiC MESFETs With Improved Trap Models
- 2010
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Ingår i: IEEE Transactions on Electron Devices. - 1557-9646 .- 0018-9383. ; 57:3, s. 729-732
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Tidskriftsartikel (refereegranskat)abstract
- Measured and simulated transient characteristics ofa SiC metal–semiconductor field-effect transistor are compared. Self-heating, gate tunneling, substrate, and surface traps are taken into account in the simulations. By explicitly filling surface traps at the vicinity of the gate during pinchoff, close correspondence between simulated and measured gate lags is achieved.
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| 17. |
- Nilsson, Per-Åke, 1964, et al.
(författare)
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An InP MMIC process optimized for low noise at Cryo
- 2014
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Ingår i: Technical Digest - IEEE Compound Semiconductor Integrated Circuit Symposium, CSIC. - 1550-8781. - 9781479936229
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Konferensbidrag (refereegranskat)abstract
- An InP MMIC process was developed and optimized for ultra-low noise amplifiers (LNAs) operating at cryogenic temperature. The amplifiers from the process are working up to 100 GHz. The processed wafers are 4" and can carry more than 4000 3-stage units. For a significant number of 6-20 GHz 3-stage LNAs we have measured an average noise temperature of 5.8 K at ambient temperature of 10 K, state of the art in this frequency range, and 66.3 K at 300K. Associated gain was 35.9 dB (10K) and 33.2 dB (300 K). The standard deviation at room temperature for 47 LNAs was 1.5 K for the noise and 0.3 dB for the gain.
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| 18. |
- Nilsson, Per-Åke, 1964, et al.
(författare)
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Cryogenic Low Noise Amplifiers in an InP HEMT MMIC Process
- 2016
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Ingår i: Asia-Pacific Microwave Conference, APMC 2015, Nanjing, China, 6-9 December 2015. ; 1, s. Art. no. 7411746-
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Konferensbidrag (refereegranskat)abstract
- An indium phosphide HEMT MMIC process was developed for ultralow noise amplifiers (LNAs) at cryogenic temperatures. The process was run on 4” wafers and utilized 130 nm gate-length HEMTs. Several wide band LNAs were made in a frequency range between 1 GHz and 100 GHz. A Ka band LNA had a minimum noise temperature of 10 K and a gain of 35 dB.
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| 19. |
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| 20. |
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| 21. |
- Schleeh, Joel, 1986, et al.
(författare)
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Cryogenic 0.5-13 GHz low noise amplifier with 3 K mid-band noise temperature
- 2012
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Ingår i: IEEE MTT-S International Microwave Symposium Digest. - 0149-645X. - 9781467310871
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Konferensbidrag (refereegranskat)abstract
- A 0.5-13 GHz cryogenic MMIC low-noise amplifier (LNA) was designed and fabricated using a 130 nm InP HEMT process. A packaged LNA has been measured at both 300 K and 15 K. At 300 K the measured minimum noise temperature was 48 K at 7 GHz. At 15 K the measured minimum noise temperature was 3 K at 7 GHz and below 7 K within the entire 0.5-13 GHz band. The gain was between 34 dB and 40 dB at 300 K and between 38 dB and 44 dB at 4 K.
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| 22. |
- Schleeh, Joel, 1986, et al.
(författare)
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Cryogenic LNAs for SKA band 2 to 5
- 2017
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Ingår i: IEEE MTT-S International Microwave Symposium Digest. - 0149-645X. - 9781509063604 ; , s. 164-167
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Konferensbidrag (refereegranskat)abstract
- Four ultra-low noise cryogenic MMIC LNAs suitable for the Square Kilometer Array (SKA) band 2 to 5 (0.95-13.8 GHz) have been designed, fabricated, packaged and tested. The LNAs are based on 4×50, 8×50 and 16×50 μm HEMTs, designed for stable cryogenic operation, allowing the combination of good noise performance and return loss. The lowest noise temperatures measured in the four bands were 1.0 K, 1.2 K, 1.6 K and 2.6 K, respectively.
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| 23. |
- Schleeh, Joel, 1986, et al.
(författare)
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Passivation of InGaAs/InAlAs/InP HEMTs using Al2O3 atomic layer deposition
- 2011
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Ingår i: Conference Proceedings - International Conference on Indium Phosphide and Related Materials. 2011 Compound Semiconductor Week and 23rd International Conference on Indium Phosphide and Related Materials, CSW/IPRM 2011, Berlin, 22-26 May 2011. - 1092-8669. - 9781457717536
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Konferensbidrag (refereegranskat)abstract
- InGaAs/InAlAs/InP HEMTs (InP HEMTs) passivated by Al2O3 atomic layer deposition (ALD) demonstrated improved DC performance compared to Si3N4 plasma enhanced chemical vapour deposition (PECVD). DC measurements have been performed on 130 nm gate-length devices before and after passivation. An increase in maximum drain current density of 20% and extrinsic transconductance of 30% were observed after both ALD and PECVD device passivation. In comparison to PECVD passivated InP HEMTs, ALD passivated devices demonstrated a full suppression of a kink in the I-V characteristics associated with surface traps.
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| 24. |
- Schleeh, Joel, 1986, et al.
(författare)
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Ultralow-Power Cryogenic InP HEMT With Minimum Noise Temperature of 1 K at 6 GHz
- 2012
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Ingår i: IEEE Electron Device Letters. - : Institute of Electrical and Electronics Engineers (IEEE). - 0741-3106 .- 1558-0563. ; 33:5, s. 664-666
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Tidskriftsartikel (refereegranskat)abstract
- We present in this letter an InGaAs/InAlAs/InP high-electron-mobility transistor (InP HEMT) with record noise temperature at very low dc power dissipation. By minimizing parasitic contact and sheet resistances and the gate current, a 130-nm-gate-length InP HEMT was optimized for cryogenic low-noise operation. When integrated in a 4- to 8-GHz three-stage hybrid low-noise amplifier operating at 10 K, a noise temperature of 1.2 K +/- 1.3 K at 5.2 GHz was measured. The gain of the amplifier across the entire band was 44 dB, consuming only 4.2 mW of dc power. The extracted minimum noise temperature of the InP HEMT was 1 K at 6 GHz.
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| 25. |
- Sudow, Mattias, 1980, et al.
(författare)
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A highly linear double balanced Schottky diode S-band mixer
- 2006
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Ingår i: IEEE Microwave and Wireless Components Letters. - 1558-1764 .- 1531-1309. ; 16:6, s. 336 - 8
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Tidskriftsartikel (refereegranskat)abstract
- A high-level double balanced SiC Schottky diode mixer in SiC monolithic microwave integrated circuit (MMIC) technology has been designed, processed and characterized. The mixer is a single ended in- and output circuit with coupled transformers as baluns to enable a compact design, resulting in a total area of 2.2×2.2mm2. The mixer has a maximum IIP3 of 38dBm and IIP2 of 58dBm at 3.3GHz, and a typical P1 dB of 23dBm in the S-band. The minimum conversion loss was 12dBm at 2.4GHz. The high power operation of the mixer shows that SiC MMIC can perform well in high microwave radiation environments
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