Browsing by Author "Tarng, Jenn-Hwan"

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A Capacitively-Loaded PIFA Based Reader Antenna for Portable RFID Application
(2010)
Wu, Sung-Jung
;
Chao, Chi-Hung
;
Tarng, Jenn-Hwan
;
電信工程研究所
;
Institute of Communications Engineering
A capacitively loaded planar inverted F antenna (PIFA) for a portable RFID application is presented. The antenna consists of four parts: a ground plane, a rectangular radiator with cut slots, an excited stub, and a shorting pin on the right-hand side that connects the ground plane to the rectangular radiator. The excited stub and the rectangular radiator are forms capacitive coupling. The capacitive coupling and shorting pin are used to effectively reduce the antenna size. Parametric studies of the proposed antenna are discussed to understand the operating mechanism and to produce a brief design guideline. The proposed antenna is easy to integrate in radio frequency devices for low manufacturing costs.
A Compact Dual Notched Bands CPW-Fed Slot Antenna
(2018-01-01)
Lin, Chu-Huan
;
Cheng, Wen-Chi
;
Wu, Sung-Jung
;
Tarng, Jenn-Hwan
;
電信工程研究所
A compact dual notched bands CPW-fed slot antenna is presented. The antenna consists of a wideband CPW-fed slot antenna and four connected slots which can create the impedance mismatch in the unwanted bands. Furthermore, the evolution of the proposed antenna is used to illustrate the band notched operation. The measured results agreed with the simulated results confirm the good omnidirectional radiation patterns with flat gains in the wanted bands but strong gain suppression in the unwanted bands. The proposed antenna can be used in the 2G/5GHz WLAN operation with over 14 dB gain suppression in 2.78-3.36 GHz and 4.03-4.76 GHz bands. The proposed antenna can be easily integrated with other mobile communication devices for its small size, 27(L) X 21 (W) mm(2), and planar structure is suitable for multiband wireless applications.
A Compact Folded PIFA for UWB On-Body Communications
(2016)
Chan, Wen-Chih
;
Chen, Keng-Hsien
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Tarng, Jenn-Hwan
;
電信工程研究所
;
Institute of Communications Engineering
A compact folded planar inverted F antenna (PIFA) for ultra wideband (UWB) on-body communications is proposed. A tapered shape is employed into the radiating plate of the proposed antenna for wideband impedance matching. For size miniaturization, both the radiating plate and the grounding plate are folded. The folded radiating plate is designed to correspond to and be close to the folded grounding plate to create a capacitive load and to lower the resonant frequency for further size miniaturization. Due to the compact thickness of the proposed antenna, it can be easily attached to the human body with comfort. The grounding plate, the grounding plate is used as a reflector to steer radiation along the surface of human body as well as enhance the transmission efficiency of on-body communications. The proposed antenna covers the bandwidth from 6 to 10 GHz with 5 similar to 7 dBi radiation gain, which is suitable for on-body communications.
A Compact Planar Dual-Band Filtering Antenna
(2017-01-01)
Yen, Jui-Hsien
;
Liu, Nai-Chen
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Chen, Keng-Hsien
;
Tarng, Jenn-Hwan
;
電信工程研究所
A compact planar dual-band filtering antenna is proposed. The design concepts in this paper achieve compacted size and reduce restrictions in the dual-band filtering antenna design. The filtering antenna utilizes an inverted U-shaped coupled line and a T-shaped feeding structure to compact the size without performance deterioration. A two-stage stepped-impedance resonator (SIR) is exploited for dual-band filtering. The SIR is bent into U-shape, and part of the inner ground is rectangularly slotted for Y-shaped antenna. The simulated and measured results show that proposed filtering antenna achieves operating frequency bands in 2.37 to 2.55 GHz and 4.93 to 5.73 GHz with peak radiation gain of 2 and 3.3 dBi, respectively. The proposed structure facilitates the dual-band filtering antenna design.
A Compact Size Four-Leaf Clover Shaped Antenna for On-Body Communications
(2016)
Chen, Keng-Hsien
;
Liu, Nai-Chen
;
Tarng, Jenn-Hwan
;
電信工程研究所
;
Institute of Communications Engineering
A compact size four-leaf clover shaped antenna for on-body communication is proposed. The proposed antenna consists of four antenna elements which are based on antipodal Vivaldi antennas (AVA). The combination of the four antenna elements is made for omnidirectional radiation in parallel to the surface of the human body. To achieve a compact combination of four AVA elements, the conducting planes around the tapered slot of AVA elements are bent. The contours of the tapered slot are optimized for wideband impedance matching. An overlap between AVA elements is created to obtain capacitive load and to reduce resonant length. The influence of the proximity of the human body on the proposed antenna is inapparent. The proposed antenna is built on the FR4 substrate with the size of 46 x 46 x 0.6 mm(3) and the bandwidth of 6 to 10.6 GHz, which is suitable for on-body communication applications.
A Filtering Diplexing Antenna for Dual-Band Operation With Similar Radiation Patterns and Low Cross-Polarization Levels
(2017-01-01)
Lee, Yun-Jui
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Tarng, Jenn-Hwan
;
Chung, Shyh-Jong
;
電信工程研究所
;
Institute of Communications Engineering
A novel filtering diplexing antenna for dual-band operation is presented. The antenna is composed of a slot-loaded patch and two resonators with a commonly used ground. Dog-bone-shaped slots are used on the ground for achieving broadside magnetic coupling and increasing the isolation between operating bands. The antenna design is based on a second-order Chebyshev bandpass filter synthesis. The proposed antenna exhibits high band-edge selectivity performance, low cross-polarization levels with half-power beamwidths greater than 86 degrees for 2.4- and 5.2-GHz WLAN communication bands. The measured and simulated results are highly consistent.
A Frequency Reconfigurable Slot Antenna Using PIN Diodes
(2009)
Chen, Keng-Hsien
;
Wu, Sung-Jung
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Kang, Cheng-Hung
;
Chan, Chao-Kai
;
Tarng, Jenn-Hwan
In this paper, a frequency reconfigurable slot antenna using PIN diodes is proposed. The proposed structure is based on an open-end straight slot line on the bottom layer and a microstrip line input on the top layer. By means of the two PIN diodes and the associated dc bias network, the proposed antenna has the ability to alternatively switch the operating frequency. The proposed antenna is made of FR4 substrate and use commercial PIN diodes. The measured results agree with simulated results, and further verify the design concept. The proposed antenna can be applied in the commercial wireless communication due to its low cost and low profile properties.
A low-power CMOS LNA for ultra-wideband wireless receivers
(2007-05-10)
Lee, Yi-Ching
;
Tarng, Jenn-Hwan
;
電信工程研究所
;
Institute of Communications Engineering
In this paper, a low-power ultra-wideband (UWB) low-noise amplifier (LNA) is proposed. Here, we propose a structure to combine the common gate with band pass filters, which can reduce parasitic capacitance of the transistor and to achieve input wideband matching. The pi-section LC network technique is employed in the LNA to achieve sufficient. at gain. A bias resistor of large value is placed between the source and the body nodes to prevent body effect and reduce noise. Numerical simulation based on TSMC 0.18 mu m 1P6M process. It achieved 10.0 similar to 12.4 dB gain from 3 GHz to 10.6 GHz and 3.25 dB noise figure in 8.5 GHz, operates from 1.5 V power supply, and dissipates 3 mW without the output buffer.
A Low-Power Self-Forward-Body-Bias CMOS LNA for 3-6.5-GHz UWB Receivers
(2010-02-01)
Li, Chen-Ming
;
Li, Ming-Tsung
;
He, Kuang-Chi
;
Tarng, Jenn-Hwan
;
電信工程研究所
A low-power low-noise amplifier (LNA) implemented in 0.18 mu m CMOS technology utilizing a self-forward-body-bias (SFBB) technique is proposed for UWB low-frequency band system. By using the SFBB technique, it reduces supply voltage as well as saves additional bias circuits, which leads to low power consumption of 4.5 mW with low supply voltage of 1.06 V for two drain-to-source voltage drops. The complementary architecture and direct coupling technique between the first two stages also save bias circuits. The measurement result shows that the proposed LNA presents a maximum power gain of 16 dB with a good input impedance matching (S11 < -12 dB) and an average noise figure of 2.65 dB in the frequency range of 3-6.5 GHz.
A Low-Profile Dipole RFID Tag Antenna with Lateral Omni-Directional Radiation Properties for Cold-Chain Logistics Applications
(2014-01-01)
Chen, Keng-Hsien
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Yen, Jui-Hsien
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Tarng, Jenn-Hwan
;
Yang, Chang-Fa
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傳播研究所
In this paper, a low-profile dipole RFID tag antenna with a lateral omni-directional pattern is presented. The proposed low-profile antenna can be easily integrated into a size-limited RFID module. To achieve the lateral omni-directional pattern, two shorting pins are added in this antenna structure, which performs better in stacking environments. Therefore, the proposed antenna is suitable for cold-chain logistics applications.
A Multi-eared Antenna with Frequency and Polarization Reconfigurability
(2011)
Chen, Keng-Hsien
;
Chen, Jhao-Ru
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Wu, Sung-Jung
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Tarng, Jenn-Hwan
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電控工程研究所
With the rapid development of cognitive radio technology, reconfigurable antennas are getting more and more attention. In general, the design of reconfigurabilities and impedance matching of reconfigurable antennas is individually achieved by different parts of antenna structure. However, designs of this kind increases switching mechanism complexity and the cost of antennas. This paper presents an innovative multi-eared antenna with frequency and polarization reconfigurability. The proposed ear-like structures can concurrently control and influence the resonant frequency, phase, and antenna impedance to simultaneously achieve the design of frequency reconfigurability, polarization reconfigurability, and impedance matching. The proposed antenna demonstrates that it can switch its frequency to 3.2 GHz, 3.35 GHz, or 3.5 GHz with linear polarization (LP); or it can switch its polarization to linear, left hand, or right hand circular polarization (LHCP/RHCP) at 3.35 GHz. The simulated and measured results of the proposed antenna indicate that it possesses good impedance bandwidth and axial ratio (AR). Hence, the proposed reconfigurable antenna is well suited to wireless communication applications.
A Multiband Quasi-Yagi Type Antenna
(2010-02-01)
Wu, Sung-Jung
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Kang, Cheng-Hung
;
Chen, Keng-Hsien
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Tarng, Jenn-Hwan
;
電信工程研究所
A new design of multiband quasi-Yagi type antenna for 700 MHz band, GSM900, DCS1800, GPS, and Bluetooth/WLAN applications is presented. In contrast to conventional quasi-Yagi antenna design, our proposed antenna realizes the multiband performance by interaction between the section extended ground and the derived driver element which is a branch of driver dipole element. The parametric studies of the proposed antenna are discussed to explore the antenna operating mechanism. The performances of the antenna are demonstrated along with measured and simulated results.
A Notched-Band UWB Planar Monopole Antenna using the Tapped-line Coupled Resonator
(2009)
Wu, Sung-Jung
;
Kang, Cheng-Hung
;
Chen, Keng-Hsien
;
Chan, Chao-Kai
;
Tarng, Jenn-Hwan
In this paper, we propose a band-notched monopole antenna for ultra-wideband applications. The notched band, 5GHz WLAN band, is created by using a proper-positioned tapped-line coupled resonator on a fork-shaped radiator center. The proposed antenna also features flat gain frequency response, small varied group delay and 10 to 18dB gain suppression in the notched band. Details of the antenna are discussed along with measured and simulated results.
A novel design of high-speed divide-by-3/4 counter for a dual-modulus prescaler
(2006-06-25)
Shih, Yi-Shing
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Tarng, Jenn-Hwan
;
電信工程研究所
;
Institute of Communications Engineering
A novel design for a high-speed divide-by-3/4 counter is presented. The proposed design reduces not only the critical path delay but also the feedback path delay, hence it can increase the operating speed. With this divide-by-3/4 counter, a divide-by-127/128 dual-modulus prescaler (DMP), implemented in 0.18 mu m CMOS technology, shows a maximum operating frequency of 7.0 GHz with 2.4mW power consumption at 1.8V supply voltage, which has 25% speed improvement and still consumes less power as well compared to the recently-reported one.
A Novel Folded UWB Antenna for Wireless Body Area Network
(2012-02-01)
Kang, Cheng-Hung
;
Wu, Sung-Jung
;
Tarng, Jenn-Hwan
;
交大名義發表
;
National Chiao Tung University
A novel folded ultrawideband antenna for Wireless Body Area Network (WBAN) is proposed, which can effectively reduce the backward radiation and proximity effects of human bodies. The proposed antenna has a low-profile 3D structure that consists of a bevel-edge feed structure and a metal plate with folded strip. The bevel edge feed structure achieves broadband impedance matching and the metal plate acts as the main radiator. Moreover, the folded strip not only extends the lower frequency band but also provides additional resonant frequency around 6 GHz. The final bandwidth covers from 3.1 GHz to 12 GHz. The proposed antenna shows the directional patterns with low backward radiation due to the patch-like structure and the ground plane also prevents from the proximity effects of human bodies. Furthermore, the simulated SAR values of the proposed antenna are lower than the values of omnidirectional disc planar monopole. These features demonstrate that the proposed antenna is suitable for WBAN application.
A Novel Modified Multiband Planar Inverted-F Antenna
(2009)
Yu, Ya-Chung
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Tarng, Jenn-Hwan
;
電信工程研究所
;
Institute of Communications Engineering
A novel multiband modified planar inverted-F antenna (PIFA) with a compact single feed is proposed, which covers GSM900 (880-960 MHz), DCS (1710-1880 MHz), PCS (1850-1990 MHz), UMTS (1920-2170 MHz), Bluetooth/WLAN (2400-2480 MHz), WiMAX (2500-2690 MHz), HiperLAN/2 (5470-5725 MHz), and an additional band (4600-4800 MHz). In conventional PIFA, most of time the shorted pin acts as a capacitor load only for impedance matching purpose, which may yield a large ground plane, narrow bandwidth, and large antenna volume due to a long shorted pin to provide enough capacitance. In our design, the shorted pin just acts a short-circuited load, which is an effective way to control the current resonant paths and is a novel way in design a multiband PIFA. Furthermore, with this design and parasitic folded structures, the proposed multiband antenna can be modeled by parallel short-circuited transmission line impedance transformers (TLIT), which can easily create six mentioned frequency bands (from PCS band to HiperLAN/2 band) by adjusting the lengths of folded branches. Measurement result conforms that our multiband design not only provides size reduction of both the antenna and the ground plane but also enhances the bandwidth of the six bands.
A novel stability-based routing protocol for mobile ad-hoc networks
(2007-04-01)
Tarng, Jenn-Hwan
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Chuag, Bing-Wen
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Wu, Fang-Jing
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資訊工程學系
;
電信工程研究所
The dynamics of Mobile Ad-hoc NETworks (MANETs), as a consequence of mobility of mobile hosts, pose a problem in finding stable multi-hop routes for communication between a source and a destination. Traditional ad-hoc routing protocols are proposed to find multi-hop routes based on shortest path routing algorithms, which cannot effectively adapt to time-varying radio links and network topologies of MANETs. In this paper, a novel stability-based ad hoc routing protocol, which is named as Ad-hoc On-demand Stability Vector (AOSV) routing protocol, is proposed to properly and effectively discover stable routes with high data throughput and long lifetime by considering the radio propagation effect on signal strength. Here, a stochastic mobile-to-mobile radio propagation model is proposed to predict path loss as well as received signal strength between adjacent nodes, and the estimation of link/route stability is derived from the prediction of signal strength. With awareness of link and route stabilities, a path finding algorithm is designed to explore the stable route with largest route stability for a source and destination pair. The performance of AOSV protocol is compared with the well-known Ad-hoc On-demand Distance Vector (AODV) routing protocol and other related works. Simulation results indicate that the AOSV routing protocol leads to significant throughput increases up to 70% improvement comparing to AODV, and provides better performance than related works.
A Novel Three-Dimensional Hybrid Spatial Model for Wideband MIMO Channel in Indoor Environments
(2010)
Tarng, Jenn-Hwan
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Chang, Wei-Ju
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Wu, Sung-Jung
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電機工程學系
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Department of Electrical and Computer Engineering
Studies of the effects of three-dimensional (3D) propagations on MIMO channel correlation and capacity have been presented in some literatures based on given 3D stochastic models of angle spectrum. However, it is only for narrowband MIMO channels and can not properly include specular reflections due to walls and/or the ground. In this letter, a hybrid spatial channel model, which combines a 3D ray-tracing based model for deterministic rays with a new 3D model for single-bounce randomly scattering rays, is proposed to investigate wideband spatial/polarized MIMO channel correlation. Based on the proposed model, the per-tap correlation among MIMO sub-channels is formulated and is validated by indoor measurements. From the comparison between measured and computed sub-channel correlations, it is found that our 3D model is more accurate than the 2D model, which only considers the propagation path in the horizontal plane, for both the co-polarized and the cross-polarized antenna cases. It is noted that the concept of effective scattering region is introduced in our model, which can increase computation efficiency without sacrifice the prediction accuracy.
A Reduced-Size Wide Slot Antenna for Enhancing Along-Body Radio Propagation in UWB On-Body Communications
(2014-03-01)
Shay, Wen-Tron
;
Jan, Shiou-Chiau
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Tarng, Jenn-Hwan
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傳播研究所
;
Institute of Communication Studies
In this paper, a 6-10-GHz ultrawideband (UWB) directional reduced-sizewide slot antenna (RWSA) for on-body wireless communications is proposed and investigated. The RWSA is designed to be narrow in width and can be mounted on the side of a wireless device. When a side-mounted RWSA is worn on a body, the antenna boresight is naturally directed along the body surface, and most of the energy can be efficiently transmitted by direct or diffracted waves. Consequently, the on-body channel performance can be effectively improved. After a series of on-body channel measurements, the results show that, with the side-mounted RWSAs, the path loss is significantly improved (greater than 20 dB) compared with the results of previous studies, and the sensitivity of the channel to the human body and environment is effectively lessened. An approach to estimate the variation range of path loss in real environments is also proposed at the end of this paper.
A relay node deployment method for disconnected wireless sensor networks: Applied in indoor environments
(2009-05-01)
Tarng, Jenn-Hwan
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Chuang, Bing-Wen
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Liu, Pei-Chen
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電信工程研究所
;
Institute of Communications Engineering
In this paper. a 2-D geometric and adaptive relay node deployment method with polynomial-time complexity is proposed to reduce relay nodes for bridging all disconnected node pairs of a wireless sensor network (WSN). In this method, proper locations for placing relay nodes are discovered on a plane, which gives a much larger degree of freedom to compare with the traditional 1-D search algorithm. In this way, the deployed relay node can bridge as many disconnected node pairs as possible around it. Besides, the method can also adapt to radio environments because that a sophisticated propagation model including large-scale path loss, shadowing, and multipath fading effects is used to estimate link connectivity. Simulation result validates its robustness and efficiency compared with the existing relay node deployment methods. The proposed method significantly reduces the total number of relay nodes compared with the related works in all of the investigated indoor environments. (C) 2008 Elsevier Ltd. All rights reserved.