Browsing by Author "Wen, SY"

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A fully integrated 5.2 GHz GaInP/GaAs HBT upconversion micromixer with output LC current combiner and oscillator
(2003-01-01)
Meng, CC
;
Hsu, SK
;
Peng, AS
;
Wen, SY
;
Huang, GW
A 5.2 GHz; upconversion micromixer with output LC current combiner and integrated oscillator is demonstrated in 2 mum GaInP/GaAs HBT technology in this paper. Micromixer has a single-ended input and a passive LC current combiner is used to convert mixer differential output into a single-ended output. A cross-coupled LC oscillator with oscillation frequency of 4.3 GHz; and a cascode buffer amplifier are also integrated in the same chip. The die size is 1 mm(2). The fully integrated upconversion micromixer has conversion gain of -2.5 dB, OP1dB of -12.5 dBm and 40 dB RF-IF isolation when input IF=0.9 GHz and thus output RF=5.2 GHz. The IF input return loss is better than 25 dB for frequencies up to 6 GHz: while RF output return loss is better than 12 dB for frequencies from 5.15 GHz; to 5.35 GHz.
A fully integrated 5.2 GHz GaInP/GaAs HBT upconversion micromixer with output LC current combiner and oscillator
(2003)
Meng, CC
;
Hsu, SK
;
Peng, AS
;
Wen, SY
;
Huang, GW
A 5.2 GHz upconversion micromixer with output LC current combiner and integrated oscillator is demonstrated in 2 mum GaInP/GaAs HBT technology in this paper. Micromixer has a single-ended input and a passive LC current combiner is used to convert mixer differential output into a single-ended output. A cross-coupled LC oscillator with oscillation frequency of 4.3 GHz and a cascode buffer amplifier are also integrated in the same chip. The die size is 1 mm(2). The fully integrated upconversion micromixer has conversion gain of -2.5 dB, OP1dB of -12.5 dBm and 40 dB RF-IF isolation when input IF=0.9 GHz and thus output RF=5.2 GHz. The IF input return loss is better than 25 dB for frequencies up to 6 GHz while RF output return loss is better than 12 dB for frequencies from 5.15 GHz to 5.35 GHz.
Variable optical attenuator with tunable nonsmooth curved mirror
(2004-11-01)
Lin, CH
;
Wen, SY
;
Hsu, WY
;
機械工程學系
;
Department of Mechanical Engineering
The attenuate effect of a variable optical attenuator (VOA) with a tunable nonsmooth curved mirror is fabricated and investigated experimentally and analytically. The working principle of this VOA is based on tuning the reflective mirror membrane into the nonsmooth curved mirror to enhance the optical attenuation, compared with that of the smooth curved mirror. The attenuation depending on the radius of curvature in a smooth concave mirror is simulated. Also, the attenuation tests on smooth and nonsmooth concave mirrors are conducted experimentally. The mirror membrane of the proposed VOA can provide not only the curved shape, but also a nonsmooth shape at the same time in the mirror membrane. By comparing the experimental results between the smooth and nonsmooth curved mirrors, the attenuation is shown to be enhanced at least 60% by the nonsmooth effect when the radius of curvature is smaller than 50 mm. The mirror membrane combining gold and low-stress nitride using back-side etching is sufficiently flat to provide an insertion loss of 0.53dB, and more than 40dB attenuation after deformation.