Browsing by Author "Hwang, Ruey-Bing"

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A Cylindrical Metamaterial Mirror (Invited Paper)
(2015)
Hwang, Ruey-Bing
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資訊工程學系
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電機學院
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Department of Computer Science
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College of Electrical and Computer Engineering
This paper reports the scattering of electromagnetic plane wave by a synthetic dielectric made of one-dimensional (1D) periodically stratified dielectric layers along the radial direction. Interestingly, the bi-static echo width of the synthetic dielectric in a specific frequency range of operation is almost identical to that of a perfect mirror having the same dimension. In comparison with the noble metal having significant dielectric loss in optics, such a synthetic dielectric has excellent performance in serving as a reflection mirror but with insignificant loss.
A Spatial Beam Splitter Consisting of a Near-Zero Refractive Index Medium
(2012-01-01)
Hwang, Ruey-Bing
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Hsu, Neng-Chieh
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Chin, Cheng-Yuan
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電機工程學系
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Department of Electrical and Computer Engineering
A novel metamaterial-based beam splitter is demonstrated in this communication. The metamaterial is a three-dimensional (3 D) fishnet structure arranged in a two-dimensional (2 D) square lattice. According to Snell's law, the refracted wave from medium into air tends to be normal to the interface if the effective refractive index of medium is approximately zero. In light of this concept, the study presents a metamaterial with near-zero effective refractive index and an internal line source inside as excitation. Metallic flares with specific tilting angle were installed at four sides of the beam splitter to reduce reflection coefficient and match the impedance of the fishnet structure and free space. In addition to calculating the phase relation of eigenwaves in the metamaterial, this study measures the radiation patterns to verify its spatially beam-splitting characteristics.
An adaptive multi-beam massive array architecture for 5G wireless
(2015)
Hwang, Ruey-Bing
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Tsai, Yi-Che
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Hsiao, Cherng-Chyi
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資訊工程學系
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電機學院
This paper reports an adaptive multi-beam forming architecture designed for 5G wireless communication system. As far as a beam-forming system is concerned, the adjustment of the phase angle and weighting on each radio frequency (RF) signal connected to antenna element should be taken into account. Here, the phased local oscillator (LO) is employed for replacing the commonly used phase shifter, and the baseband I-and Q-signal strength is altered for designating the weighting on the RF signal. Additionally, two procedures are performed for accomplishing the dynamical beam forming. Firstly, the switched-beam circuit on the subarray determine the desired radiation zone. Secondly, the beam-steering within the zone is then achieved by varying the phase angle of phased LO and the amplitude over the baseband I/Q signals. Notably, each of the steerable beam contributed by an array consisting of several subarrays can be independently generated to accomplish a massive array system having multiple steerable beams
An Impedance Matching Technique for Bandwidth Enhancement of Terminal Antennas
(2014)
Hsiao, Cherng-Chyi
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Huang, Hsien-Tung
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Hwang, Ruey-Bing
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電機學院
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電機工程學系
Built-in antennas for terminal devices are inherently electrically small which is usually difficult to meet satisfactorily the specifications in bandwidth and efficiency for applicable operation. A simplified real frequency technique was employed in this paper for impedance matching of a DVB-H antenna and a GSM 850/900 antenna. Trade off of antenna realized gain and band width has been considered to optimize the antenna performance.
AN X-BAND EIGHT-SUBARRAY SMART ANTENNA SYSTEM FOR DIRECTION OF ARRIVAL ESTIMATION
(2014-11-01)
Tseng, Yau-Hwa
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Su, Ing-Jiunn
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Hwang, Ruey-Bing
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交大名義發表
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電機資訊學士班
An X-Band eight-subarray smart antenna system has been developed in this article to demonstrate its capability of direction of arrival estimation for correlated arriving signals. The antenna array is composed of an eight-subarray antenna and eight-track of transceiver for quadrature baseband to RF up/down conversion. Multiple classification of signal (MUSIC) and modified MUSIC algorithm with spatial smoothing are used for high resolution angle of arrival (AoA) estimation. Measured results showed that the modified MUSIC algorithm with spatial smoothing is capable of estimating target AoA with average angle error of 1.14 degrees when target arriving angles are varying from -30 degrees to 30 degrees. Accurate results of AoA estimation by simulation and measurement for stationary or dynamic targets has also been demonstrated to validate the feasibility of the proposed X-Band smart antenna system. (C) 2014 Wiley Periodicals, Inc.
Broadband cloaking using composite dielectrics
(2011-03-01)
Hwang, Ruey-Bing
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Chin, Cheng-Yuan
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電機工程學系
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Department of Electrical and Computer Engineering
In this paper, we present a novel cloaking structure that is able to make a metallic block invisible in a metallic waveguide. Such a cloak is made up of a stack of commonly used dielectric slabs. We carry out the numerical simulation and observe the detour of the vector Poynting power through the cloak. Moreover, the experiment is conducted for measuring the scattering characteristics including the reflection and transmission coefficients. The great improvement in the transmission coefficient in a broad bandwidth after cloaking is demonstrated. Significantly, the theory of mode conversion is developed for explaining the cloaking phenomenon. Copyright 2011 Author(s). This article is distributed under a Creative Commons Attribution 3.0 Unported License. [doi:10.1063/1.3562891]
Capacity Comparison for CSG and OSG OFDMA Femtocells
(2010)
Tsai, Ang-Hsun
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Huang, Jane-Hwa
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Wang, Li-Chun
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Hwang, Ruey-Bing
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交大名義發表
The low-power and low-cost femtocells can improve indoor coverage and capacity. However, when femtocells are deployed extensively, the serious two-tier interference problem occurs. The method to access the femtocell is the key to manage the interference in the femtocell systems. In this paper, we investigate the impacts of access methods and directional antenna on link reliability and capacity for the orthogonal frequency-division multiple access (OFDMA)-based femtocell systems. Simulation results show that the open access method can improve the femtocell capacity over the traditional closed access method. Nevertheless, under the link reliability requirement of indoor and outdoor users, the improvement in femtocell capacity due to open access method is minor. Thanks to the narrow-beam pattern, the switched-beam directional antenna can be used to further reduce the interference and enhance the capacity. It is shown that the open access method using the switched-beam antenna can achieve higher femtocell capacity than that using the omnidirectional antenna.
Combining the switched-beam and beam-steering capabilities in a 2-D phased array antenna system
(2016-01)
Tsai, Yi-Che
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Chen, Yin-Bing
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Hwang, Ruey-Bing
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傳播研究所
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電機學院
This paper presents the development, fabrication, and measurement of a novel beam-forming system consisting of 16 subarray antennas, each containing four aperture-coupled patch antennas, and the application of this system in smart wireless communication systems. The beam patterns of each of the subarray antennas can be switched toward one of nine zones over a half space by adjusting the specific phase delay angles among the four antenna elements. Furthermore, when all subarrays are pointed at the same zone, slightly continuous beam steering in around 1 degrees increments can be achieved by dynamically altering the progressive phase delay angle among the subarrays. Phase angle calibration was implemented by coupling each transmitter output and down converter into the in-phase/quadrature baseband to calculate the correction factor to the weight. In addition, to validate the proposed concepts and the fabricated 2-D phased array antenna system, this study measured the far-field radiation patterns of the aperture-coupled patch array integrated with feeding networks and a phase-calibration system to carefully verify its spatially switched-beam and beam-steering characteristics at a center frequency of 2.4GHz which can cover the industrial, scientific, and medical band and some long-term evolution applications. In addition, measured results were compared with calculated results, and agreement between them was observed.
Design, Fabrication, and Characterization of Novel Vertical Coaxial Transitions for Flip-Chip Interconnects
(2009-05-01)
Wu, Wei-Cheng
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Chang, Edward Yi
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Hwang, Ruey-Bing
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Hsu, Li-Han
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Huang, Chen-Hua
In this paper, a novel transition design using vertical "coaxial transition" for coplanar waveguide (CPW-to-CPW) flip-chip interconnect is proposed and presented for the first time. The signal continuity is greatly improved since the coaxial-type transition provides more return current paths compared to the conventional transition in the flip-chip structure. The proposed coaxial transition structure shows a real coaxial property from the 3-D electromagnetic wave simulation results. The design rules for the coaxial transition are presented in detail with the key parameters of the coaxial transition structure discussed. For demonstration, the back-to-back flip-chip interconnect structures with the vertical coaxial transitions have been successfully fabricated and characterized. The demonstrated interconnect structure using the coaxial transition exhibits the return loss below 25 dB and the insertion loss within 0.4 dB from dc to 40 GHz. Furthermore, the measurement and simulation results show good agreement. The novel coaxial transition demonstrates excellent interconnect performance for flip-chip interconnects and shows great potential for flip-chip packaging applications at millimeter waves.
Electromagnetic Interference in Substrate-Integrated Waveguides Circuit and Its Suppression Technique
(2010-01-01)
Hwang, Ruey-Bing
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Chin, Cheng-Yuan
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Lin, Yu-De
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Kitazawa, Toshihide
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Wu, Chang-Yu
As was well known, the substrate-integrated waveguide can be easily implemented and integrated with active and passive devices using the printed circuit process. Thus, the integration circuit and system based on the substrate integrated waveguide technique becomes achievable. However, in the integrated circuit environment, the close proximity between adjacent substrate-integrated waveguides may cause the electromagnetic coupling, and thus the electromagnetic interference problem arises accordingly. In this research, we demonstrate the electromagnetic coupling between two parallel substrate integrated waveguide. Moreover, the theory of Fabry-Perot resonator was employed to explain the resonance coupling between the substrate-integrated waveguides. On the other hand, a new substrate-integrated waveguide equipped with moats [1] was utilized to examine the capability of cross-talk suppression. Interestingly, we find that in comparison with the conventionally used substrate-integrated waveguide the new one can effectively suppress the electromagnetic wave coupling. Therefore, the signal integrity can be further improved in a microwave or millimeter-wave circuit or system implemented using the substrate-integrated waveguide technique.
High Capacity Femtocells with Directional Antennas
(2010)
Tsai, Ang-Hsun
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Huang, Jane-Hwa
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Wang, Li-Chun
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Hwang, Ruey-Bing
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傳播研究所
Femtocells are low-power, low-cost and user-deployed home base stations that can improve poor indoor coverage and enhance system capacity. However, as femtocells are deployed extensively, the two-tier interference will become serious, including the interference from macrocells and that from femtocells. Thanks to the low side lobe, the E-plane horns based reconfigurable antenna can be used to reduce the interference and enhance the capacity. In this paper, we investigate the effects of applying E-plane horns based reconfigurable directional antenna on link reliability and capacity of the orthogonal frequency-division multiple access (OFDMA) based femtocell systems. We compare our newly designed E-plane horns based reconfigurable antenna, and the sector antenna provided in the IEEE 802.16m, as well the omni-directional antenna. It is shown that E-plane horns based reconfigurable antenna system has higher femtocell capacity than the IEEE 802.16m sector antenna system due to the advantages of low side lobe and high main-lobe gain.
High-Capacity OFDMA Femtocells by Directional Antennas and Location Awareness
(2012-06-01)
Tsai, Ang-Hsun
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Wang, Li-Chun
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Huang, Jane-Hwa
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Hwang, Ruey-Bing
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電機工程學系
"In this paper, we propose a location-aware mechanism combined with a low-cost four-sector switched-beam directional antenna to enhance the spectrum efficiency of orthogonal frequency-division multiple access (OFDMA)-based femtocell systems. The considered location-awareness capability is specified in the current IEEE 802.16m WiMAX standard, but has not been applied to avoid the interference between indoor femtocells and outdoor macrocells. With the knowledge of the locations of outdoor users, the proposed four-sector switched-beam antenna in a femtocell can effectively avoid the interference among femtocells and macrocells by adjusting the number of OFDMA subcarriers used at each femtocell. Numerical results show that the proposed approach can significantly improve spectrum efficiency compared to the existing methods."
High-Isolation X-Band Marine Radar Antenna Design
(2014-05-01)
Kuo, Fang-Yao
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Hwang, Ruey-Bing
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電機工程學系
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Department of Electrical and Computer Engineering
This paper presents a high-isolation printed antenna array for marine radar applications. The antenna array is composed of 32 identical square microstrip patches operated at a center frequency of 9.35 GHz and includes a 100-MHz bandwidth (subject to a 1.5:1 voltage standing wave ratio [VSWR]). The patch antennas are arranged in four arms, each of which contains eight elements and is series-fed using Chebyshev tapering (25 dB side-lobe level). To apply the antenna in marine radar applications, an antenna with horizontal polarization was employed because, in comparison with vertical polarization, it can relatively reduce the sea clutter reflectivity. Therefore, a slit was carved on each patch element to change the current path, thereby enabling horizontal polarization. The antenna gain, 3-dB beamwidth, side-lobe level, and front-to-back ratio were 22 dBi, 5.3 degrees, 26.4 dB, and 38.5 dB, respectively. Additionally, metallic baffles were introduced for increasing the isolation between the transmitting and receiving antennas to 60 dB.
Highly improved convergence approach incorporating edge conditions for scattering analysis of graphene gratings
(2020-07-30)
Hwang, Ruey-Bing
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交大名義發表
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National Chiao Tung University
This research developed an effective and efficient approach for improving the slow convergence in the scattering analysis of a one-dimensional graphene grating, made of a periodic array of parallel graphene strips, illuminated by a TM-polarized plane wave. Specifically, the electric fields over the graphene strips and slit regions in a unit cell are individually expressed as an expansion of local basis functions inherently satisfying edge conditions. Interestingly, convergence rate is highly improved compared to the customary and modified Fourier modal method. Additionally, with the aid of local basis functions, the Gibbs phenomenon occurring at both edges of graphene strip can be removed.
Reflection characteristics of a composite planar AMC surface
(2012-03-01)
Hwang, Ruey-Bing
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Tsai, Yueh-Lin
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電機工程學系
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Department of Electrical and Computer Engineering
This study investigates the reflection characteristics of a composite Artificial Magnetic Conductor (AMC) surface consisting of multiple orthogonal gradient AMC surfaces arranged in a two-dimensional periodic pattern. The gradient AMC surface in this study consists of square metal patches of variable size printed on a grounded dielectric substrate. Due to the orthogonal placement of the gradient AMC surface, the incident energy of a plane wave normally incident on the composite AMC surface will be reflected into four major lobes away from the impinging direction. To achieve a systematical design, a simple formula based on array antenna theory was developed to determine the reflection pattern of the gradient AMC surface illuminated by a normal incident plane wave. A time-domain full-wave simulation was also carried out to calculate the electromagnetic fields in the structure and the far-field patterns. The scattering patterns of the structure were measured in an electromagnetic anechoic chamber. Results confirm the design principle and procedures in this research. Since such a composite AMC surface can be easily fabricated using the standard printed circuit board technique without via-hole process, it may have potential applications in beam-steering and radar cross section reduction. Copyright 2012 Author(s). This article is distributed under a Creative Commons Attribution 3.0 Unported License. [doi: 10.1063/1.3682352]
Rigorous Formulation of the Scattering of Plane Waves by 2-D Graphene-Based Gratings: Out-of-Plane Incidence
(2014-09-01)
Hwang, Ruey-Bing
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交大名義發表
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電機資訊學士班
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National Chiao Tung University
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Undergraduate Honors Program of Electrical Engineering and Computer Science
The plane wave scattering by 2-D gratings is studied by a rigorous mode-matching technique. Specifically, the grating considered in this work is made of periodically patterned graphene. Due to the 2-D periodicity, the electromagnetic fields in the uniform medium are expressed in terms of characteristic Floquet solutions, with each space harmonic representing a plane wave solution consisting of both and constituents. By imposing the boundary condition on the tangential components of the electromagnetic fields at the graphene interface via the conductivity tensor of graphene, one can set up an input-output relation expressed in terms of the generalized scattering matrix. For a planar multilayer structure consisting of a finite stack of 2-D graphene-based gratings, the overall scattering characteristics can be obtained by cascading each of the input-output relations of the 2-D grating successively.
Scattering characteristics of cylindrical metamaterials
(2016-03-01)
Hwang, Ruey-Bing
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Huang, Hsien-Tung
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電機資訊學士班
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Undergraduate Honors Program of Electrical Engineering and Computer Science
This paper reports the scattering of electromagnetic plane wave by annular metamaterials composed of concentric regular dielectric layers of infinite length. Interestingly, in certain frequency ranges, their scattering properties are similar to those of a perfect electric conductor cylinder, except that the tangential electric field on their surfaces does not vanish. Moreover, the frequency bands of total reflection spectra can be rigorously predicted using Floquet-Bloch theorem. (C) 2016 Author(s).
Time-Division Multiplexing Monopulse Antenna System for DVB-SH Application
(2015-02-01)
Tsai, Yueh-Lin
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Hwang, Ruey-Bing
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電機學院
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College of Electrical and Computer Engineering
This study involved developing a time-division multiplexing monopulse antenna system for tracking the DVB-SH signal operated in S-band. Such a system consists of a mode-former circuit and a stacked circularly polarized antenna array, which was implemented using planar-printed circuit technology. In the mode-former circuit, a four-way power splitter comprising Wilkinson power dividers and four switched-line phase shifters were employed to provide 0 degrees/180 degrees phase angles at each output port. The sum-and-difference angle discriminators were implemented along vertical and horizontal planes for detecting the incident elevation and azimuth angles. The stacked circularly polarized antenna array, composed of four edge-fed patches on the bottom layer and four corresponding parasitic patches, were exploited on the top layer to increase the axial ratio bandwidth. The experimental results revealed that, at 2.185 GHz, the null depth of the difference patterns were -34.2 dB and -33.2 dB along the two principal planes.
Vertical Transmission Structure
(2009-10-29)
Chang, Edward Yi
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Wu, Wei-Cheng
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Hwang, Ruey-Bing
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Hsu, Li-Han
A vertical transmission structure for high frequency transmission lines includes a conductive axial core and a conductive structure surrounding the conductive axial core. The vertical transmission structure is applied to a high-frequency flip chip package for reducing the possibility of underfill from coming in contact with the conductive axial core.
Wireless pwer transfer through low-e glass
(2019-01-01)
Shan, Shengming
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Hsiao, Vincent
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Hwang, Ruey-Bing
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電信工程研究所
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Institute of Communications Engineering
Delivering power wirelessly and efficiently through low-e glass window is critical for successful deployment of 5G Fixed Wireless Access services. This research reports the effect of low-emissivity glass on wireless power transfer using magnetic-field resonant coupling technique. The hybrid electromagnetic-circuit method is employed to formulate the input-output relation of the power at transmit- and receive-coils, particularly in the presence of low-emissivity (e) glass. The equivalent circuit model of the low-e glass is developed to integrate the structure/material into circuit analysis.