Browsing by Author "Yu, SH"

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A micromachined silicon-submount package for vertical emission of edge emitting laser diodes
(2000-05-15)
Shie, JS
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Yu, SH
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光電工程學系
;
Department of Photonics
A silicon-submount package structured with vertical emission of edge emitting laser diodes (LDs) is addressed. Utilizing the micromachining technique, a (100) silicon wafer can be engraved into a batch of submount structures having 45 degrees-slant mirrors for light deflection, and mesas for precise die dwelling. The mirrors are fabricated by deep V-groove etching with the etching window aligned to [100] crystal direction, and by multiple cycles of oxidation-and-isotropic etching processes. The initial ridged surface can thus be polished to a final roughness below 30 nm, with 100-mu m depth, sufficient to accommodate the vertically extended angle of a laser beam. Gold plating on the surface is patterned to form reflective mirrors on the slopes individually, and to provide the bases, which are connected to common electrode, for electroplating of thick indium pads selectively on the mesa areas. Self-alignment of LD bars or dice soldered right on the mesas can be achieved by the surface-tension mechanism that existed between the LD gold electrodes and the indium pads during melting. With simple TO-5 package, a vertically emitted beam has been observed on a stacked LD-submount device, as expected. (C) 2000 Elsevier Science S.A. All rights reserved.
Analysis and design of 1-bit noise-shaping quantizer using variable structure control approach
(2004)
Hu, JS
;
Yu, SH
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電控工程研究所
;
Institute of Electrical and Control Engineering
This paper introduces a straightforward analysis of a 1-bit noise-shaping quantizer using variable structure control methods. The method using the concept of equivalent control to access the bound on state signals when the sliding condition is reached. Simulation examples and an experimental circuit using off-the-shelf electronic components are given to demonstrate the theoretical analysis.
Analysis and design of a single-bit noise-shaping quantizer
(2003)
Yu, SH
;
Hu, JS
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電控工程研究所
;
Institute of Electrical and Control Engineering
Noise-shaping quantization is the use of feedback to improve the effective resolution of a coarse quantizer. Based on the theory of sliding modes, this study presents a simple and effective approach to analyzing and designing a single-bit noise-shaping quantizer. The derived stability conditions and accurate estimates of the state bounds make an exact design possible.
Analysis and design of one-bit noise-shaping quantizer using variable structure control approach
(2005-09-01)
Hu, J
;
Yu, SH
;
電控工程研究所
;
Institute of Electrical and Control Engineering
This paper offers a straightforward analysis of a one-bit noise-shaping quantizer based on variable structure control methods. The method uses the concept of equivalent control to access the bound on the state signals when the sliding condition is reached. For a stable loop filter, the global stability can be proved to exist by using the Lyanpunov stability theory. For an unstable loop filter, this paper proposes a state constraint approach to ensure that the sliding condition is achieved. Simulation examples and an experimental circuit constructed using off-the-shelf electronic components are given to demonstrate the correctness of the theoretical analysis.
Application of model-matching techniques to feedforward active noise controller design
(1998-01-01)
Hu, JS
;
Yu, SH
;
Hsieh, CS
;
電控工程研究所
;
Institute of Electrical and Control Engineering
In this paper, three digital model-matching techniques in H-2, H-infinity, and l(1) performance measures are applied to design digital feedforward controllers for active noise cancellation in ducts. Different measures account for different optimization objectives in terms of physical signals. The distributed nature and high-bandwidth requirements of the control system result in a large set of parameters in plant description and these design techniques proved to be useful insolving the controllers numerically. Experiments were conducted using a floating-point digital signal processor that produced broad-band noise reduction. Design variations and noise reduction effects in terms of human perception are also discussed. It is experimentally proved that using model-matching designs, the causality principle originally raised by Paul Lueg does not have to be satisfied in order to actively reduce the noise level.
Application of model-matching techniques to feedforward active noise controller design
(1998-01-01)
Hu, JS
;
Yu, SH
;
Hsieh, CS
;
電控工程研究所
;
Institute of Electrical and Control Engineering
In this paper, three digital model-matching techniques in H-2, H-infinity, and l(1) performance measures are applied to design digital feedforward controllers for active noise cancellation in ducts. Different measures account for different optimization objectives in terms of physical signals. The distributed nature and high-bandwidth requirements of the control system result in a large set of parameters in plant description and these design techniques proved to be useful insolving the controllers numerically. Experiments were conducted using a floating-point digital signal processor that produced broad-band noise reduction. Design variations and noise reduction effects in terms of human perception are also discussed. It is experimentally proved that using model-matching designs, the causality principle originally raised by Paul Lueg does not have to be satisfied in order to actively reduce the noise level.
Asymptotic rejection of periodic disturbances with fixed or varying period
(2001-09-01)
Yu, SH
;
Hu, JS
;
電控工程研究所
;
Institute of Electrical and Control Engineering
A constructive derivation of repetitive control is obtained, through attempting to derive a control law for asymptotic rejection of periodic disturbances. This derivation not only reveals a close relationship between iterative operator inversion and repetitive control, but also suggests a unified design method for a learning control algorithm. Also, based on the observation, digital repetitive control can be generalized to reject periodic disturbance whose period is not exactly an integer multiple of the sampling interval, This study introduces a delay filter in the digital repetitive control law, which optimally interpolates the signal between samples, thus effectively reconstructing the signal of the previous period and making the learning process of repetitive control successful. The proposed optimal delay filter can be updated easily according to different signal periods. Thus it is specifically suitable for on-line timing when the signal period is changing. Compared with the available tuning methods, the proposed tuning method has excellent steady-state performance while maintaining fast transient and system robustness. The simulations on active noise cancellation within a duct confirm the superiority of this tuning method.
Controller design for active noise cancellation headphones using experimental raw data
(2001-12-01)
Yu, SH
;
Hu, JS
;
電控工程研究所
;
Institute of Electrical and Control Engineering
This work presents a practical method of designing controllers for active noise cancellation (ANC) headphones. Without attempting system identification and perturbation modeling, the headphone system is directly described by a set of frequency-response data. In frequency domain, the controller synthesis problem is formulated as a constrained optimization problem, where the Ha performance objective is minimized with various frequency-dependent constraints. The fixed-order robust controller is thus designed to achieve maximum noise attenuation with acceptable stability margins. Further, the method is able to accurately constrain noise amplification outside control bandwidth due to waterbed effect of nonminimum phase plants. This feature is very important for the ANC design to maintain an overall quality of noise reduction.
Optimal MISO repetitive control system design using mixed time and frequency domain criteria
(1998-03-01)
Hu, JS
;
Yu, SH
;
Huang, SC
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電控工程研究所
;
Institute of Electrical and Control Engineering
This paper presents an optimal repetitive controller design approach when both frequency and time domains criteria are considered. These criteria include limited control force, convergence rate, and robustness. In particular, the design formulation is based on MISO (multiple-input-single-output) plants which aim at solving nodal point problems encountered in flexible dynamic systems. Nodal points represent physical constraints for feedback control, especially when their frequencies are within the control bandwidth. If multiple control paths with distinct nodal frequencies are available, the proposed method is able to design controllers to compensate the effect and reach certain design objectives. The ellipsoid algorithm is used to calculate controllers' parameters. Experiments were conducted to demonstrate the proposed method.
Optimal synthesis of a fractional delay FIR filter in a reproducing kernel Hilbert space
(2001-06-01)
Yu, SH
;
Hu, JS
;
電控工程研究所
;
Institute of Electrical and Control Engineering
Based on a bandlimited signal model, the optimal fractional delay finite impulse response (FIR) filter and corresponding interpolating error bound is derived in a reproducing kernel Hilbert space. The resulting optimal filtering is a projection onto a prescribed finite dimensional subspace, The connection of this filtering accuracy to the delay time and the filter order is investigated via error analysis.