In this paper, a high power and high efficiency L/S-band GaN HEMT with tungsten nitride (WN) Schottky barrier is presented. By employing WN Schottky barrier, the reaction between the gate electrode and AlGaN layer is ...
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In this paper, a high power and high efficiency L/S-band GaN HEMT with tungsten nitride (WN) Schottky barrier is presented. By employing WN Schottky barrier, the reaction between the gate electrode and AlGaN layer is minimized and the Schottky barrier reveals good thermal stability. At 2.2 GHz, the developed GaN HEMT with 1.25 mm gate periphery delivers an output power density of 3.3W/mm with 75% maximum power-added efficiency (PAE). The accelerated life test shows that the mean time to failure (MTTF) of the developed devices is 1.8×10 7 hours at 150°C channel temperature with an activation energy of 1.5 e V. Output power more than 90 W and PAE about 70% are obtained with a 2×12 mm gate periphery packaged device between 1.14 GHz and 1.24 GHz.
A simple method to accurately determine the nonlinear dependence of the thermal resistance of heterojunction bipolar transistors(HBTs)on ambient and junction temperatures is presented.A nonlinear model of the therma...
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ISBN:
(纸本)9781467324748
A simple method to accurately determine the nonlinear dependence of the thermal resistance of heterojunction bipolar transistors(HBTs)on ambient and junction temperatures is presented.A nonlinear model of the thermal resistance dependence on the power dissipation is introduced for the actual junction temperature *** method is demonstrated by an accurate extraction of thermal effects of a power HBT with an effective emitter area of 1×15μm2,fabricated with an in-house InP HBT technology.
A generalized parallel-plate dielectric waveguide(G-PPDW)is proposed as a new guiding medium for terahertz wave.A theoretical analysis of the transmission characteristics for the TE modes of this generalized structure...
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A generalized parallel-plate dielectric waveguide(G-PPDW)is proposed as a new guiding medium for terahertz wave.A theoretical analysis of the transmission characteristics for the TE modes of this generalized structure is *** are presented for the field components,dispersion,power ratio,transmission loss and characteristic impedance as functions of the operating frequencies,dimensions and material *** the case of the lowest-order mode TE10,design curves covering frequencies and dimensions for the given material constants in the THz region are *** theoretical results of transmission characteristics obtained from these equations are verified by the finite-element method with a good *** investigation results show that by selecting proper dimensions and dielectric materials,G-PPDW can be used to guide THz waves efficiently with high power confinement and low *** outstanding properties may open up a way to many important applications for THz integratedcircuits and systems.
A monolithic AlGaN/GaN HEMT voltage controlled oscillator (VCO) using barium strontium titanate (BST) MIM varactor is reported first time. The BST thin film was fabricated by RF magnetron sputtering. The fabrication p...
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A monolithic AlGaN/GaN HEMT voltage controlled oscillator (VCO) using barium strontium titanate (BST) MIM varactor is reported first time. The BST thin film was fabricated by RF magnetron sputtering. The fabrication p...
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A monolithic AlGaN/GaN HEMT voltage controlled oscillator (VCO) using barium strontium titanate (BST) MIM varactor is reported first time. The BST thin film was fabricated by RF magnetron sputtering. The fabrication process is fully compatible with the standard GaN MMIC integrated process. An output power of 17dBm and the phase noise of -75dBc/Hz (at 100kHz) and -110dBc/Hz (at 1MHz) are obtained while the bias of the drain is 8V and BST varactor voltage is 0V. The VCO exhibits 500MHz tunable frequency bandwidth at the central frequency of 6.42GHz while BST varactor voltage changed from 0V to 20V.
InAlN/GaN heterojunction structures are grown on two-inch c-face(0001) sapphire substrates by metalorganic chemical vapour deposition. AlN and AlGaN interlayers are intentionally inserted into the structure to impro...
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InAlN/GaN heterojunction structures are grown on two-inch c-face(0001) sapphire substrates by metalorganic chemical vapour deposition. AlN and AlGaN interlayers are intentionally inserted into the structure to improve the electrical properties. The lowest sheet resistance of 359 Ω/sq and the highest room-temperature two-dimensional electron gas (2DEG) mobility of 1051 cm2 V-1s-1 is obtained in the structure with AlN thickness of 1.3 nm. The structure with AlN thickness of 2 nm exhibits the highest 2DEG concentration of 1.84×1013 cm-2. The sample with an AlGaN interlayer gives a smoother surface morphology compared to the one using an AlN interlayer, indicating potential applications of this technique in device fabrication.
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