Browsing by Author "Chen, Keng-Hsien"

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A Compact Folded PIFA for UWB On-Body Communications
(2016)
Chan, Wen-Chih
;
Chen, Keng-Hsien
;
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
;
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 Frequency Reconfigurable Slot Antenna Using PIN Diodes
(2009)
Chen, Keng-Hsien
;
Wu, Sung-Jung
;
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-Profile Dipole RFID Tag Antenna with Lateral Omni-Directional Radiation Properties for Cold-Chain Logistics Applications
(2014-01-01)
Chen, Keng-Hsien
;
Yen, Jui-Hsien
;
Tarng, Jenn-Hwan
;
Yang, Chang-Fa
;
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
;
Wu, Sung-Jung
;
Tarng, Jenn-Hwan
;
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
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Chen, Keng-Hsien
;
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.
Compact four bands hybrid filtering antenna using step impedance resonators and tuning stub transition structures
(2018-06-13)
Chen, Keng-Hsien
;
Lo, Yu-Chen
;
Lee, Yi-Shi
;
Wu, Sung-Jung
;
Tarng, Jenn-Hwan
A novel compact four bands hybrid filtering antenna composed of a hybrid radiator and a four bands bandpass filter is presented. The hybrid radiator is constructed using the micro-strip line fed, the square-ring and the T-stub near the ground plane. The proposed four bands bandpass filter is composed of two parts, one is two-step impedance resonators (SIRs) and the other is the tuning stub transition structure. With tuning stub transition structure, two SIRs effectively match to 50 hybrid radiator. Furthermore, the geometry of the proposed filter is U-shaped with the micro-strip fed around the hybrid radiator. The evolution of the hybrid radiator and the construction of the four bands bandpass filter using the two SIRs and the transitions are discussed in detail. The proposed filtering antenna not only possesses numerous operation bands with good band edge gain selectivity but also reduces the occupied size in the modern communication device. The overall size of the proposed filtering antenna is 33mmx36.4mmx0.508mm, and the operation frequencies are 1.8/2.45/3.5/5.2GHz bands for GSM1800/WLAN/WiMAX applications. The measured results agree with simulated outcomes.
High Directional Compact PIFAs for the Indoor Position Searching Scheme
(2017-01-01)
Liao, Shao-Chun
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Wu, Sung-Jung
;
Chen, Keng-Hsien
;
Tarng, Jenn-Hwan
;
電信工程研究所
High directional compact PIFAs for the indoor position searching scheme is presented. In this paper, each proposed PIFA uses parametric and optimized design to compact the size. And the size of each PIFA is 5.2 x 23.5 mm(2). Four proposed PIFAs are placed in the circular PCB in order to achieve the indoor position searching scheme by using RSSI method. An effective beam angle of each PIFA is 90 degrees. Therefore, four PIFAs have covered 360 degrees radiation in xy-plane. The peak gain of the proposed PIFA is 2.5 dBi and the front-to-back ratio is more than 18 dB. The measurement shows the proposed PIFAs and the searching scheme are suitable for indoor positioning applications.
Study of an Ultrawideband Monopole Antenna With a Band-Notched Open-Looped Resonator
(2010-06-01)
Wu, Sung-Jung
;
Kang, Cheng-Hung
;
Chen, Keng-Hsien
;
Tarng, Jenn-Hwan
;
交大名義發表
A novel band-notched planar monopole ultrawideband (UWB) antenna is proposed. A notched band, located in the 5 GHz WLAN band, is created using a resonator at the center of a fork-shaped antenna. The resonator is composed of an open-looped resonator and two tapped lines. With the open-looped resonator, the antenna has a good band-notched performance and bandstop-filter-like response in the target band. A parametric study of the notched bandwidth is described that explored the antenna operating mechanism. Then, an equivalent circuit model illustrates the band-notched behaviors more clearly. The antenna input admittance calculated with the equivalent circuit model reasonably agrees with the HFSS simulated result. The proposed antenna also features flat gain frequency responses, small varied group delay and 15 to 35 dB gain suppression at the notched band. Accordingly, the band-notched antenna can effectively select target bands by adjusting these antenna parameters.
Wide Slot Antennas for UWB On-Body Communications
(2014-01-01)
Shay, Wen-Tron
;
Chen, Keng-Hsien
;
Tarng, Jenn-Hwan
;
傳播研究所
;
Institute of Communication Studies
In this paper, two modified ultra-wideband (UWB) wide slot antennas (WSAs) designed for antenna diversity in on-body communications are proposed. One antenna is a dual-polarization WSA (DPWSA) for polarization diversity. The other is a reduced-size WSA (RWSA), which is designed to be narrow in width and can be mounted on the side of a wireless device. Pattern diversity can be achieved by using two or more side-mounted RWSAs oriented in different directions. Both DPWSA and RWSA have broad impedance bandwidths and do not substantially increase the size of the original antenna or wireless device. The proposed diversity antennas can be used to mitigate the fading effects in on-body communications.