Browsing by Author "Lin, Ren-Jie"

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A circular CPW-fed slot antenna resonated by the circular loop for broadband circularly polarized radiation
(2008-05-01)
Deng, I-Chung
;
Ke, Qing-Xiang
;
Lin, Ren-Jie
;
King, Yueh-Tsu
;
電子工程學系及電子研究所
The coplanar waveguide (CPW) fed circular slot antenna, resonated by the circular loop with a narrow opening, is designed for obtaining broadband circularly polarized (CP) radiation. The length of protruded signal strip (L-S) is utilized to adjust the phase difference between two orthogonal field components in the circularly polarized waves. In this design, the proposed antenna has the minimum return loss of -56.5 dB at the frequency of 2.403 GHz. The impedance and 3 dB axial-ratio bandwidths can reach up to 740 MHz or 33.3% and 390 MHz or 16.6%, respectively. In addition, the simulated results are about as good as those of the measured ones. (C) 2008 Wiley Periodicals, Inc.
A novel design of a CPW-fed single square-loop antenna for circular polarization
(2008-09-01)
Deng, I-Chung
;
Lin, Ren-Jie
;
Ke, Qing-Xiang
;
Huang, Jia-Min
;
Chang, Kow-Ming
The experimental and simulated results for the proposed antenna are investigated in this article. Moreover, a novel broadband design of a circularly polarized (CP) single square slot antenna fed by a single coplanar waveguide is presented. By appropriately choosing the circumference of the square-loop, the length of the protruded strip, and the gap, this proposed antenna thus owns good CP radiation and good impedance match simultaneously at the frequency of 2.45 GHz. This proposed antenna has the fundamental resonant frequency of 2.5 GHz with the minimum return loss of -39.9 dB. Furthermore, its impedance bandwidth is 460 MHz or 18.4% and 3-dB axial-ratio (AR) bandwidth is 360 MHz or 14.4% at 2.5 GHz.
A novel design of a CPW-fed square slot antenna with broadband circular polarization
(2006-12-01)
Chang, Kow-Ming
;
Lin, Ren-Jie
;
Deng, I-Chung
;
Chen, Jin-Bo
;
Xiang, Ke Qing
A novel design of a broadband circularly polarized square slot antenna fed by a single coplanar waveguide is proposed and discussed. The circularly polarized radiation is achieved by means of using an outer rectangular ring and an inner rectangular ring at the center of a square slot. The proposed antenna has the fundamental resonant frequency of 2.44 GHz with the return loss of -40.93 dB, and it has the bandwidth of 3 dB axial ratio of 420 MHz or (17.21%). Details of the results are presented and discussed. (c) 2006 Wiley Periodicals, Inc.
A novel design of a microstrip-fed shorted square-ring slot antenna for circular polarization
(2007-07-01)
Chang, Kow-Ming
;
Lin, Ren-Jie
;
Deng, I-Chung
;
Ke, Qing-Xiang
;
電子工程學系及電子研究所
The design of a circularly polarized slot antenna fed by a single microstrip line is presented. The circularly polarized radiation is achieved by means of using a shorted square-ring slot. This proposed antenna has the fundamental resonant frequency of 2.4 GHz with the minimum return loss of -50.44 dB. The impedance bandwidth is 930 MHz or 38.7% referred to the resonant frequency, and it also has the 3-dB axial-ratio (AR) bandwidth of 310 MHz or 12.9% referred to the resonant frequency. In addition, this proposed antenna shows good performance of circular polarization (CP) radiation with the range of the lower 3-dB AR value covering elevation angles between -40 to 40 degrees. (C) 2007 Wiley Periodicals, Inc.
Design of low-temperature CMOS-process compatible membrane fabricated with sacrificial aluminum layer for thermally isolated applications
(2007-03-15)
Chang, Kow-Ming
;
Lin, Ren-Jie
;
Deng, I-Chung
;
電子工程學系及電子研究所
;
Department of Electronics Engineering and Institute of Electronics
In the surface micromachining technique, residual stress and sticking effect play an important role in determining whether a microstructure is suspended or collapse during a release process. In this paper, we propose a simpler method for making suspended membranes for thermally isolated application by using cheap processing steps and compatible with CMOS-process; also, there are some simulations done to predict stiction as function of the anchor profile. It is demonstrated by fabricating the test structures of CMOS-process compatible surface micromachined bolometer using aluminum sacrificial layer with high yield and high throughput. The aluminum sacrificial layer provides some benefits including rapid wet-etching and high wet-etching selectivity with respect to dielectric materials. The residual stress and gravity of the microstructures are evaluated with structural simulations, and the sticking effect can be alleviated by an appropriate structure design and a release process. Once the residual stress is known, we can successfully use Coventorware simulations to predict a suspended membrane by controlling the anchor profile which contains sidewall conformal factor and sidewall angle. The simulation results are in good agreement with the experiments. (c) 2006 Elsevier B.V. All rights reserved.