Browsing by Author "Wang, Yu-Shin"

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A compact slot antenna utilizing a right/left-handed transmission line feed
(2008-03-01)
Wang, Yu-Shin
;
Hsu, Min-Feng
;
Chung, Shyh-Jong
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電信工程研究所
;
Institute of Communications Engineering
A novel compact planar antenna utilizing cascaded right/left-handed transmission lines is proposed. The significance of layout planning with respect to radiation is investigated and discussed in this paper. Two segments of transmission lines of the same electrical length with opposite signs are cascaded to provide zero phase at the operation frequency. The closed-form formulas for the equivalent circuit of a transmission line are used for circuit design. Both antenna layout and radiation mechanism are discussed. For experimental demonstration, the proposed antenna operating at 2.45 GHz was implemented on an FR4 substrate. The topology using several patches has quite smaller size than the conventional patch antenna. Besides, a fairly omnidirectional radiation pattern was measured.
A Crossed-slot Coupled Patch Antenna Array with Wedge Design for DBS Reception
(2008)
Wang, Yu-Shin
;
Tsai, Y. -Y.
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Chung, Shyh-Jong
;
交大名義發表
;
National Chiao Tung University
A Decoupling Technique for Increasing the Port Isolation Between Two Strongly Coupled Antennas
(2008-12-01)
Chen, Shin-Chang
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Wang, Yu-Shin
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Chun, Shyh-Jong
;
電信工程研究所
;
Institute of Communications Engineering
A compact decoupling network for enhancing the port isolation between two closely spaced antennas is proposed in this paper. In the network, we first connect two transmission lines (TLs) individually to the input ports of two strongly coupled antennas. The length of the TLs is designed so that the trans-admittance between ports changes from a complex one at the antenna inputs to a pure imaginary one. A shunt reactive component is then attached in between the TL ends to cancel the resultant imaginary trans-admittance. Finally, a simple lumped-element circuit is added to each port for input impedance matching. The even-odd mode analysis is adopted to investigate the currents excited on the antennas for predicting the radiation pattern of the two-element antenna array. Two examples of printed antennas at 2.45 GHz are tackled by using the proposed decoupling structure. The measurement results agree quite well with the simulation ones. High antenna isolation and good input return loss are simultaneously achieved in both cases, which demonstrates the feasibility of the structure. The decoupled antenna array in each example radiates, as prediction, toward different but complementary directions when the input power is fed in turn to the two input ports. The array efficiency is estimated better than 75% in each example. This pattern diversity effect is helpful for reducing the channel correlation in a multiple-input multiple-output (MIMO) communication system.
A Miniature Quadrifilar Helix Antenna for Global Positioning Satellite Reception
(2009-12-01)
Wang, Yu-Shin
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Chung, Shyh-Jong
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電信工程研究所
;
Institute of Communications Engineering
The design is described of a very compact quadrifilar helix antenna. A hollow ceramic rod is used as a dielectric load to reduce antenna size, which is only 2.7% of an air-loaded quadrifilar helix antenna. A simple equivalent circuit is established for the proposed quadrifilar helix antenna to demonstrate impedance characteristics. A self-phasing method for achieving circular polarization is also proposed. This method is convenient for tuning circular polarization. Additionally, a compact matching structure is designed to match the proposed antenna, which only utilizes short transmission-line sections and one capacitor. For experiments, the proposed antenna is designed at 1.575 GHz such that it can be utilized for global position system. Measurement and simulation results agree. A hemispherical pattern with a beamwidth of 150 is measured. This circular-polarized pattern with a wide beamwidth is feasible for mobile applications.
A Miniaturized Ground Edge Current Choke-Design, Measurement, and Applications
(2009-05-01)
Wang, Yu-Shin
;
Lu, Jung-Chieh
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Chung, Shyh-Jong
;
電信工程研究所
;
Institute of Communications Engineering
We propose a miniaturized microwave current choke for blocking the current flowing along the edge of a substrate's ground plane. The proposed current choke is composed of a printed inductor and a printed capacitor, which possesses a size much smaller than a conventional quarter-wavelength current choke. By introducing the choke at one side of the ground plane, an effective electrical open circuit is performed for reflecting the ground edge current. The size of the proposed ground edge current choke (GECC) is as small as around 0.06 wavelength in free space. Two applications of the GECC are presented in this paper. The first is the radiation pattern regulation of a printed monopole antenna with long ground plane. The GECC in this application reflects the induced traveling-wave current along the ground plane edge and changes it to a standing-wave one, thus regulating the tilted radiation pattern due to the traveling-wave current to a broadside pattern. The other application is the decoupling of two nearby monopole antennas. By placing the proposed compact GECC in between the antennas, it is found that the isolation between the antenna ports can be enhanced from 8 dB to 32 dB. The experimental results agree well with the simulation, which demonstrate the feasibility of the proposed GECC.
A new high isolation dual-antennas with miniature decoupling network design
(2007)
Chen, Shin-Chang
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Wang, Yu-Shin
;
Ling, Ching-Wei
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Chung, Shyh-Jong
;
電信工程研究所
A novel small planar antenna utilizing cascaded right/left-handed transmission lines
(2007)
Wu, Chien-Hung
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Hsu, Min-Feng
;
Wang, Yu-Shin
;
Chung, Shyh-Jong
;
電信工程研究所
A Short Open-End Slot Antenna With Equivalent Circuit Analysis
(2010-05-01)
Wang, Yu-Shin
;
Chung, Shyh-Jong
;
電信工程研究所
;
Institute of Communications Engineering
A novel configuration is described for a compact microstripline fed slot antenna which is shorter than one-eighth wavelength at the operating frequency. Antenna size is reduced by placing two matching capacitors at both sides of an electrically small open-end slot, through the use of a wideband antenna equivalent circuit model established by considering the physical geometry. With the proposed antenna configuration, a 2.45 GHz slot antenna is first designed using an open-end slot of size 9 mm by 1.5 mm that is originally resonant at 4.8 GHz in a conventional design. Experimental results correlate well with those of the full-wave simulation and the equivalent circuit calculation, which shows a bandwidth of 109 MHz and peak gain of 1.89 dBi. By using the same slot size, several slot antennas operating at even lower frequencies (1.9, 1.64, 1.57 GHz) are then designed and demonstrated. Nearly omni-directional radiation patterns with peak gains 0 dBi and radiation efficiencies larger than 45% are obtained. Given its simplicity and compactness, the proposed electrically small antenna is feasible for circuit integration and highly promising for wireless mobile devices.
Design of a dielectric-loaded quadrifilar helix antenna
(2006)
Wang, Yu-Shin
;
Chung, Shyh-Jong
;
電信工程研究所
;
Institute of Communications Engineering
Dual-mode millimeter-wave folded microstrip reflectarray antenna
(2008-06-01)
Tarn, I-Young
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Wang, Yu-Shin
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Chung, Shyh-Jong
;
電信工程研究所
;
Institute of Communications Engineering
A dual-mode folded microstrip reflectarray antenna was developed and demonstrated in this paper. The proposed folded reflectarray antenna contains three parts: a planar main reflector, a planar subreflector, and printed feed antennas. The main reflector is used to produce twisted reradiated fields and to provide phase compensation for focusing. The subreflector parallel with the main reflector is made of a substrate printed with high-density metal grid lines, which is transparent to perpendicularly polarized fields, but would reflect the parallel ones. Three fixed-position patch antennas with polarization parallel to the grid lines are created for the radar mode, so that the radiation beam is switchable. Another patch with perpendicular polarization is designed for communication. A simple approach was proposed for simulating and designing the folded reflectarray. Measured results show good agreement with the calculated ones.
Scheduling and Control of a Wafer Transfer Robot for Foundry Equipment Innovation Competition
(2019-01-01)
Song, Kai-Tai
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Ou, Song-Qing
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Yang, Cheng-An
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Sun, Yu-Xuan
;
Kang, Li-Ren
This paper presents a design and implementation of a wafer transfer robotic system for a Foundry Equipment Innovation Competition. In this system, a 4-DOF robotic arm was designed and constructed for wafer transfer between a cassette and processing chambers. The purpose of this competition was to promote intelligent automation for wafer fabrication, in which multiple wafers and chambers need to be handled simultaneously. A scheduling algorithm is proposed for efficient task execution of wafer to process recipes assigned during the competition. The task also features to integrate defect detection and endpoint determination of wafer processing. The robot was required to receive the processing data from the mission platform to determine the endpoint of wafer processing in a chamber and complete the recipe automatically. The online inspection algorithm detects wafer defects during the task execution and report to the task planner. The state of each wafer and chamber are taken into consideration for scheduling in order to complete the wafer fabrication in an efficient and flexible manner. The developed robotic system spent 9 minutes to complete the assigned mission of transferring 6 wafers among multiple chambers and 2 cassettes and achieved 93.4% defect-detection rate in the competition. (C) 2019, IFAC (International Federation of Automatic Control) Hosting by Elsevier Ltd. All rights reserved.
Two Nearby Dual-band Antennas with High Port Isolation
(2008)
Lui, Cai-Yi
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Wang, Yu-Shin
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Chung, Shyh-Jong
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交大名義發表
;
National Chiao Tung University
Two PIFA-related miniaturized dual-band antennas
(2007-03-01)
Wang, Yu-Shin
;
Lee, Ming-Chou
;
Chung, Shyh-Jong
;
電信工程研究所
;
Institute of Communications Engineering
There are two novel printed inverted-F antenna (PIFA) related dual-band antennas for 2.45 and 5.25 GHz; wireless local area network (WLAN) applications introduced in this paper. One is designed by spiraling the tail of the PIFA and the other is by modifying the feed structure of the PIFA into a coupling configuration. An equivalent transmission line model is proposed to explain the dual-band operation of the spiraling PIFA. The measurement results show that the former antenna has a 10 dB return loss with bandwidth 140 MHz in the 2.45 GHz frequency band and bandwidth 756 MHz at 5.25 GHz, whereas the latter one has the bandwidth 240 MHz at 2.45 GHz and bandwidth 672 MHz at 5.25 GHz. In addition, onmidirectional radiation patterns are achieved at those operating frequency bands with average antenna gains near 0 dBi. The proposed antenna possesses the properties of good performance, compact size (about 50% of a typical PIFA), low profile, and low cost; hence, it is suitable for practical applications in a combo WLAN system.