Browsing by Author "Hsiao, CC"

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A beam adjustable leaky-wave antenna using a moveable dielectric slab inside a waveguide
(2005-12-01)
Hsiao, CC
;
Hwang, RB
;
電信工程研究所
;
Institute of Communications Engineering
In this paper, we presented a beam adjustable antenna made up of a slit waveguide and a dielectric slab. In order to change the radiation main-beam angle, we changed the phase constant of the waveguide mode by inserting a dielectric slab for perturbing its field distribution. The direction of radiation main-beam can be steered by dynamically changing the position of the dielectric slab. For the theoretical analysis, the dispersion relation, including the phase and attenuation constants, was determined by solving the transverse resonance equation. An agreement between the theoretical and experimental radiation pattern verities the beamsteering mechanism. Up to 23 degrees beam-steering angle can be achieved using this approach.
Experimental and theoretical studies of the rate coefficients of the reaction O(P-3)+HCl at high temperatures
(2002-10-31)
Hsiao, CC
;
Lee, YP
;
Wang, NS
;
Wang, JH
;
Lin, MC
Rate coefficients of the reaction O(P-3) + HCl in the temperature range 1093-3197 K were determined using a diaphragmless shock tube. O atoms in the ground electronic P-3 states were generated either by photolysis Of SO2 with a KrF excimer laser at 248 nm or by pyrolysis of N2O with the shock wave. Their concentrations were monitored via atomic resonance absorption excited by emission from a microwave-discharged mixture of O-2 and He. Rate coefficients determined in this work show non-Arrhenius behavior, with values consistent with previously reported. measurements for T < 1486 K; they fit well with the equation k(1)(T) = (9.27 +/- 0.03) X 10(-24) T3.67+/-0.18 exp[-(1030 +/- 160)/T] cm(3) molecule(-1) s(-1); listed errors represent one standard deviation in fitting. Theoretical calculations at the CCSD(T)/6-311 +G(d, p) level locate a bent (3)A" (TS1) and a linear (3)A' (TS3) transition state characterized previously. On the basis of the results computed by CCSD(T)/ 6-311 +G(3df,2p)//CCSD(T)/6-311 +G(d,p), the rate coefficients predicted with conventional transition-state theory, including Eckart-tunneling corrections and with variational transition-state theory including zero- and small-curvature tunneling corrections, all agree satisfactorily with experimental observations.
Frequency-selective transmission by a leaky parallel-plate-like waveguide
(2006-01-01)
Hwang, RB
;
Hsiao, CC
;
電信工程研究所
;
Institute of Communications Engineering
The phenomena of high frequency-selective transmission of a plane wave by a dielectric two-dimensional (2-D) periodic waveguide, comprising a uniform dielectric layer sandwiched by two finite thickness 2-D periodic structures served as the waveguide wall is described. This structure is termed a leaky arallel-plate-like waveguide because the waveguide walls are U perfect reflection mirrors. The scattering characteristics and dispersion relation, including the phase and attenuation constants, of the 2-D periodic waveguide are thoroughly analyzed with the modal transmission-line method and Floquet theory. The extraordinary open stopbands caused by the contra-flow coupling between a leaky parallel-plate-like waveguide and the leaky waves, which are generated by 2-D periodic structures (waveguide walls), are displayed in the form of the Brillouin diagram. The phase-match condition is used to verify the resonant coupling between the incident plane wave and the leaky parallel-plate-like waveguide modes. Specifically, the transmission peak frequencies are accurately predicted.
Hybrid compensation control for affine TSK fuzzy control systems
(2004-08-01)
Hsiao, CC
;
Su, SF
;
Lee, TT
;
Chuang, CC
;
電機資訊學士班
The paper proposes a way of designing state feedback controllers for affine Takagi-Sugeno-Kang (TSK) fuzzy models. In the approach, by combining two different control design methodologies, the proposed controller is designed to compensate all rules so that the desired control performance can appear in the overall system. Our approach treats all fuzzy rules as variations of a nominal rule and such variations are individually dealt with in a Lyapunov sense. Previous approaches have proposed a similar idea but the variations are dealt with as a whole in a robust control sense. As a consequence, when fuzzy rules are distributed in a wide range, the stability conditions may not be satisfied. In addition, the control performance of the closed-loop system cannot be anticipated in those approaches. Various examples were conducted in our study to demonstrate the effectiveness of the proposed control design approach. All results illustrate good control performances as desired.
Improvement in wafer temperature uniformity and flow pattern in a lamp heated rapid thermal processor
(2000-07-01)
Yin, CP
;
Hsiao, CC
;
Lin, TF
;
機械工程學系
;
Department of Mechanical Engineering
An experimental lamp heated, rapid thermal processor (RTP) for an 8-in single silicon wafer was designed and established to investigate the thermal and flow characteristics in the processing chamber by transient temperature measurement and flow visualization. Experiments were carried out to explore the effects of placing a highly conducting copper plate right below the wafer on the uniformity of the wafer temperature and effects of the showerhead on the resulting flow distribution in the processing chamber. The measured data indicated that adding the copper plate can effectively reduce the nonuniformity of the wafer temperature. Besides, using a showerhead with finer holes in it results in a better flow distribution in the processor. (C) 2000 Elsevier Science B.V. All rights reserved.
Multiple access in the presence of optical-beat and co-channel interference using Walsh-code-based synchronized CDMA technique
(1997-08-01)
Hsiao, CC
;
Wang, BH
;
Way, WI
;
電信工程研究所
;
Institute of Communications Engineering
We experimentally demonstrated the feasibility of using Walsh-code-hased synchronized code-division-multiple access (S-CDMA) technique to achieve multiple access in the presence of optical-beat interference (OBI), This multiple access technique can, thus, be applied to WDMA networks using subcarrier-based common wavelength signaling, or PON's which generally do not have wavelength control on uplink laser diodes.
Multiple access in the presence of optical-beat and co-channel interference using Walsh-code-based synchronized CDMA technique
(1997-08-01)
Hsiao, CC
;
Wang, BH
;
Way, WI
;
交大名義發表
;
電信工程研究所
We experimentally demonstrated the feasibility of using Walsh-code-hased synchronized code-division-multiple access (S-CDMA) technique to achieve multiple access in the presence of optical-beat interference (OBI), This multiple access technique can, thus, be applied to WDMA networks using subcarrier-based common wavelength signaling, or PON's which generally do not have wavelength control on uplink laser diodes.
Suppression of optical beat interference using synchronised CDMA technique and in-band clipping carrier
(1997-10-23)
Wang, BH
;
Hsiao, CC
;
Way, WI
;
電信工程研究所
;
Institute of Communications Engineering
The authors propose adding a coherent in-band clipping carrier to a previously demonstrated Walsh-code-based synchronised CDMA (S-CDMA) technique to further suppress the optical beat interference (OBI). Experimental results showed thar a negligible system power penalty can be achieved even when the OBI-induced intensity noise was as high as -90.9dB/Hz. In addition, a large system dynamic range of 10dB can tx obtained to relax the tight power control requirement on S-CDMA signals.
Using preceding technique to reduce the BER penalty of an M-QAM channel in hybrid AM-VSB/M-QAM subcarrier multiplexed lightwave systems
(1998-08-01)
Chiang, PY
;
Hsiao, CC
;
Way, WI
;
電信工程研究所
;
Institute of Communications Engineering
We propose and verify through computer simulations the use of a preceding technique to eliminate the nonlinear distortions in an M-QAM channel, which is transported along with multiple AM-VSB channels by a laser diode. We show that the preceding technique can completely remove the clipping-induced bit-error-rate (BER) floor at a cost of a 3-dB signal-to-noise ratio reduction.
Using precoding technique to reduce the BER penalty of an M-QAM channel in hybrid AM-VSB/M-QAM subcarrier multiplexed lightwave systems
(1998)
Chiang, PY
;
Hsiao, CC
;
Way, WI
;
電信工程研究所
;
Institute of Communications Engineering
We propose and verify through computer simulations the use of a preceding technique to eliminate the nonlinear distortions (NLD's) in an M-QAM channel which is transported along with multiple AM-VSB channels by a laser diode. We show that the preceding technique can completely remove the clipping-induced bit-error-rate (BER) floor at a cost of a 3 dB signal-to-noise ratio (SNR) reduction.