Browsing by Author "Chao, Hsueh-Yung (Robert)"

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Automatic generation of passive equivalent circuits for broadband microstrip antennas
(2007)
Kuo, Yi-Ting
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Chao, Hsueh-Yung (Robert)
;
Li, Yiming
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電信工程研究所
;
Institute of Communications Engineering
Effect of process variation on field emission characteristics in surface-conduction electron emitters
(2008-07-01)
Lo, Hsiang-Yu
;
Li, Yiming
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Tsai, Chih-Hao
;
Chao, Hsueh-Yung (Robert)
;
Pan, Fu-Ming
In this paper, we explore the effect of process variation on field emission characteristics in surface-conduction electron emitters. The structure of Pd thin-film emitter is fabricated on the substrate and the nanometer scale gap is formed by the focused ion beam technique. Different shapes of nanogaps due to the process variations are investigated by the experiment and three-dimensional Maxwell particle-in-cell simulation. Four deformation structures are examined, and it is found that the type I exhibits high emission efficiency due to a stronger electric field around the apex and larger emission current among structures. The electron emission current is dependent upon the angle of inclination of surface. Hydrogen plasma treatment is also used to increase the edge roughness of the nanogap and thereby dramatically improve the field emission characteristics. For the nanogap with a separation of 90 nm, the turn-on voltage significantly reduces from 60 to 20 V after the hydrogen plasma treatment.
Novel surface conduction electron emitter (SCE) nanogaps for field emission displays
(2008)
Tsai, Chih-Hao
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Pan, Fu-Ming
;
Lo, Hsiang-Yu
;
Li, Yiming
;
Kuo, Yi-Ting
A novel nanometer scaled gap in palladium thin film strip was prepared by hydrogen absorption under high pressure conditions, and implemented in the fabrication of the surface conduction electron emitter (SCE) for flat panel display applications. The lattice constant increase in the Pd due to the phase transformation from the a-phase to the beta-phase after hydrogen absorption, a large compressive stress occurred to the Pd thin film. With a proper geometric arrangement of the Pd/Pt/Ti emitter electrode of the SCE structure, a single nanogap per SCE device was prepared. Finite element analysis was carried out to study the hydrostatic stress distribution in the thin film emitter structure after Pd hydrogenation, and thereby the optimized thickness of thin film electrodes of the emitter Was determined for the nanogap fabrication. The novel SCE emitter had an inclined protrusion structure on the cathode, which greatly enhance the local electrical field and improve electron beam focusing. The experimental measurement and theoretical analysis show that field emission properties of the novel SCE are superior to conventional SCE with the coplanar cathode.
Optimization of physics-based equivalent circuits for microstrip patch antennas
(2007)
Chiu, Tang-Jung
;
Kuo, Yi-Ting
;
Chao, Hsueh-Yung (Robert)
;
Li, Yi-Ming
;
電信工程研究所