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- Andersson, Christer, 1982, et al.
(författare)
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A SiC Varactor With Large Effective Tuning Range for Microwave Power Applications
- 2011
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Ingår i: IEEE Electron Device Letters. - : Institute of Electrical and Electronics Engineers (IEEE). - 0741-3106 .- 1558-0563. ; 32:6, s. 788-790
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Tidskriftsartikel (refereegranskat)abstract
- SiC Schottky diode varactors have been fabricated for use in microwave power applications, specifically the dynamic load modulation of power amplifiers. A custom doping profile has been employed to spread the C(V) over a large bias voltage range, thereby increasing the effective tuning range under large voltage swing conditions. The small-signal tuning range is approximately six, and punch through is reached at a bias voltage of -60 V, while the breakdown voltage is on the order of -160 V. An interdigitated layout is utilized together with a self-aligned Schottky anode etch process to improve the Q-factor at 2 GHz, which is 20 at zero bias and approximately 160 at punch through.
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| 2. |
- Ejebjörk, Niclas, 1984, et al.
(författare)
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Optimization of SiC MESFET for high power and high frequency applications
- 2011
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Ingår i: Materials Science Forum. - : Trans Tech Publications Inc.. - 1662-9752 .- 0255-5476. ; 679-680, s. 629-632, s. 629-632
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Konferensbidrag (refereegranskat)abstract
- SiC MESFETs were scaled both laterally and vertically to optimize high frequency and high power performance. Two types of epi-stacks of SiC MESFETs were fabricated and measured. The first type has a doping of 3×10^17 cm-3 in the channel and the second type has higher doping (5×10^17 cm-3) in the channel. The higher doping allows the channel to be thinner for the same current density and therefore a reduction of the aspect ratio is possible. This could impede short channel effects. For the material with higher channel doping the maximum transconductance is 58 mS/mm. The maximum current gain frequency, fT, and maximum frequency of oscillation, fmax, is 9.8 GHz and 23.9 GHz, and 12.4 GHz and 28.2 GHz for the MESFET with lower doped channel and higher doping, respectively.
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