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2016-06-23 PIER Letters Vol. 60, 133-140, 2016. doi:10.2528/PIERL16040202

Electromagnetic Force on Anisotropic-Conducting Film

Dan Xia

Electromechanical interaction between slow electromagnetic wave and anisotropic-conducting film is investigated. The physical effects associated with anisotropic-conducting film are revealed by electromagnetic theory and validated by experiment, and they have established the working principles for a class of electromechanical sensors and/or actuators, which have continuously moving part, and are sensitive to the amplitude and the direction of electromagnetic forces or fields and well able to reflect the resonance characteristics. The revealed and validated physical effects may have significance in quite different science and engineering fields and in wide frequency bands from RF to optics.

2016-06-03 PIER Letters Vol. 60, 127-132, 2016. doi:10.2528/PIERL16041401

A Novel Miniaturization Double Folded Quarter Mode Substrate Integrated Waveguide Filter Design in LTCC

Jian Zhou, Yong-Zhong Zhu, and Zihao Liu

A novel double-folded quarter mode substrate integrated waveguide (DFQMSIW) filter is designed in low temperature co-fired ceramic (LTCC). This filter consists of multi-layer substrate integrated waveguide. More than 93.75% of the area of the filter is effectively decreased compared with original substrate integrated waveguide (SIW) filter for the technologies of Half-Mode and Folded are applied. Meanwhile, the dimensions are further obtained reduction because of the technologies of LTCC and the vertical dimensional cavities configuration. The fabricated insertion loss and return loss are 1.9 dB and 13.5 dB, respectively.

2016-05-31 PIER Letters Vol. 60, 121-125, 2016. doi:10.2528/PIERL16031502

A Frequency Selective Surface with Polarization Rotation Based on Substrate Integrated Wavwguide

Tao Zhong, Hou Zhang, Rui Wu, and Xue-Liang Min

A frequency selective surface (FSS) with polarization rotation which provides a quasi-elliptic bandpass response is presented in this paper. Based on substrate integrated waveguide cavity (SIWC), 90 degrees polarization rotation is obtained when electromagnetic wave passes through the frequency selective surface at specially appointed polarization in a range of 16.28-16.70 GHz. Moreover, TM120/TM210 dual-mode configuration appears in the cavity within the passband. The design has been proved with high stability to electromagnetic wave of different incident angles. And the measured results in anechoic chamber provide good agreement with those from commercial software simulations.

2016-05-29 PIER Letters Vol. 60, 113-120, 2016. doi:10.2528/PIERL16041907

Genetic Algorithm Optimization for Microstrip Patch Antenna Miniaturization

Mohammed Lamsalli, Abdelouahab El Hamichi, Mohamed Boussouis, Naima Amar Touhami, and Tajeddin Elhamadi

The miniaturization of the patch antenna has become an important issue in reducing the volume of entire communication system. This paper presents an improved method of size reduction of a microstrip antenna using the genetic algorithm. The shape of a typical rectangular patch is modified in order to reduce it resonance frequency keeping the physical volume of the antenna constant. Indeed, the initial patch is divided into 10 × 10 small uniform rectangles (Pixel), and the genetic algorithm searches, the optimal configuration for the desired goal. The resonance frequency of a micro-strip patch is shifted from 4.9 GHz to 2.16 GHz and a rate of miniaturization is up to 82%. To validate the procedure, an antenna prototype has been fabricated and tested with an FR4 substrate. The measurements results were in good agreement with simulation ones.

2016-05-28 PIER Letters Vol. 60, 107-112, 2016. doi:10.2528/PIERL16041105

Compact Coaxial Probe-Fed CP Substrate Integrated Waveguide Cavity-Backed Antenna Utilizing Slot Split Ring

Jian-Quan Huang, Feng Qiu, Chunzhi Jiang, Dajun Lei, Zhenghua Tang, Ming Yao, and Qing-Xin Chu

A circularly polarized (CP) substrate integrated waveguide (SIW) cavity-backed slot antenna is proposed. A slot split ring (SSR) etched on the top metal surface of an SIW resonator is employed to generate the right-handed circularly polarized (RHCP) wave. The proposed antenna is excited directly by a coaxial probe with a proper distance from the symmetric axis of the SSR resonator. A prototype of the proposed CP antenna at the center frequency of 10 GHz is manufactured. As a result, the proposed antenna exhibits the advantages of both conventional planar antennas and metallic cavity backed antennas, including simple structure, compact size of 15.8×15.8 mm2, light weight, easy fabrication, high gain and wide axial ratio bandwidth. It is proved by experiment that an impedance bandwidth of 10.2% for the reflection coefficient less than -10 dB, an axial ratio (AR) bandwidth of 1.72% for AR less than 3 dB, and a RHCP gain 5.5 dBi have been obtained.

2016-05-27 PIER Letters Vol. 60, 101-106, 2016. doi:10.2528/PIERL16030108

Characterisation of Copper Nanoparticle Ink Printed FSS for Cellular Signals Suppression

Fauziahanim Che Seman, Nur Khalida binti Abdul Khalid, and Suhana binti Mohd Said

This paper proposes a copper nanoparticle inkprinted frequency selective surface (FSS) for cellular signals suppression. The FSS pattern is deposited on a polyimide film by using an inkjet printing technique. The printed FSS elements undergo the post-processing called sintering,where the optimum exposure duration and temperature are determined in order to form a conductive path across the metal pattern. Later, the conductivity of the printed FSS structure deposited on polyimide film is observed. The signal suppression ability of the printed FSS is conducted using the Computer Simulation Technology (CST) Microwave Studio software.

2016-05-26 PIER Letters Vol. 60, 95-100, 2016. doi:10.2528/PIERL16040801

Broadband Transition from Microstrip Line to Waveguide Using a Radial Probe and Extended GND Planes for Millimeter-Wave Applications

Azzemi Ariffin, Dino Isa, and Amin Malekmohammadi

A broadband microstrip line-to-waveguide (MSL-to-WG) transition is developed for E-band applications. In order to achieve a sufficient and broadband coupling between the microstrip line (MSL) and waveguide (WG), a radial electric probe at the end of the MSL and extended ground (GND) planes on the dielectric substrate are proposed. Results are compared against a simple transition (S-Tr) with a straight electric probe. For the case of operational bandwidth (BW) for an input return loss (S11) below -20 dB, the proposed transitions using the radial probe and extended GND planes show the BW enhancement of 33.8% and 61.9%, respectively, compared to the S-Tr. The proposed and simple transitions were fabricated on a low-loss liquid crystal polymer (LCP) dielectric substrate. The measured bandwidth (BW) for S11 below -10 dB of the proposed transition is over 28 GHz, which is satisfied at all test frequencies from 67 to 95 GHz. Its measured insertion loss can be analyzed as -1.33 and -1.41 dB per transition at 70 and 80 GHz, respectively, considering the loss contribution of the cable adapter and waveguide transition.

2016-05-24 PIER Letters Vol. 60, 89-94, 2016. doi:10.2528/PIERL16041701

A Tunable Multiband LTE Antenna for Metal-Rimmed Smartphone Applications

Xiao-Yan Zhang, Xinxing Zhong, Chuanyun Wang, and Zhiwei Liu

In this paper, a tunable multiband LTE antenna is designed for metal-rimmed smartphone applications. The antenna only uses a broken metal ring, which comprises an IFA (Inverted-F antenna) section and a parasitic section, and generates three resonant modes through this layout for the feeding point and shorting point. In addition, loading a matching circuit at the feeding point and a RF switch at shorting point of the IFA is used to switch low frequency to lower frequency. The bandwidth can completely cover 824-960 and 1710-2690 MHz. So the proposed antenna can work at GSM850, 900; DCS1800; PCS1900; WCDMA band 1, 2, 4, 5, 8; TD-SCDMA band 34, 39; CDMA BC0,BC1 and LTE band 1, 3, 7, 38, 39, 40, 41. Also, the total size of the cellphone is 150 mm×75 mm×3.5 mm, which is very suitable for 4G slim smart mobile phone applications.

2016-05-20 PIER Letters Vol. 60, 81-88, 2016. doi:10.2528/PIERL16032401

A Novel Dual-Band SIW Filter with High Selectivity

Yudan Wu, Guo Hui Li, Wei Yang, and Tong Mou

A novel dual-band substrate integrated waveguide (SIW) filter with multiple transmission zeros and good out-of-band rejection performance is presented in this paper. For this purpose, an orthogonal input/output (I/O) feeding structure directly connected to the substrate integrated waveguide (SIW) cavity is designed to split the resonant frequencies of the degenerate pair of mode. The filter can be modeled with a multi-path circuit formed by three modes (TE101, TE201 and TE102 modes) and weak cross coupling between I/O ports, thereby producing three transmission zeros which make the dual-band high selectivity. The offset of the input/output ports shifts the second transmission zero to a lower frequency from the upper passband. Several filter prototypes are designed and fabricated for demonstration, and the measured results validate the new structure for high selectivity applications.

2016-05-20 PIER Letters Vol. 60, 73-80, 2016. doi:10.2528/PIERL16030408

Microwave Characterization of Electrical Conductivity of Composite Conductors by Half-Wavelength Coplanar Resonator

Bilal Benarabi, Faouzi Kahlouche, Bernard Bayard, Anthony Chavanne, and Jeremy Sautel

The aim of this work is to characterize the electrical conductivity of composite conductors deposited on an alumina substrate. Several half-wavelength coplanar resonators are realized using several pure conductors, silver (Ag), copper (Cu), gold (Au) and tin (Sn), to compare their quality factors (Q0), related to losses, with those from analytical methods. In the literature, losses in coplanar components have been estimated by different analytical methods. We have put in evidence the relationship between electrical conductivity of the conductor and the resonator quality factor. An overall good agreement among quality factor values obtained by the analytical formulas, by numerical simulations and by microwave measurements is observed. The surface roughness is taken into account to better estimate real conductor losses. Therefore, these analytical formulas are used to extract the electrical conductivity values of the composite conductors (Ag-aC, AgSnIn and AgSn), from measured quality factors.

2016-05-19 PIER Letters Vol. 60, 67-72, 2016. doi:10.2528/PIERL16041408

CPW-Fed Stub-Loaded Slot Dipole Antenna Design for Dual-Band Operation

Jianxing Li, Jianying Guo, Hongyu Shi, Bin He, and Anxue Zhang

A novel uniplanar slot dipole antenna fed by a coplanar waveguide (CPW) is proposed for dual-band operation. The frequency ratio between the first spurious and fundamental modes of the slot dipole antenna can be conveniently adjusted with the use of four slot stubs introduced on its two arms. Furthermore, the radiation patterns at the first spurious mode are modified by adding four parasitic slots along its two arms to resemble those of the fundamental mode. Under the assistance of the slot stubs together with the parasitic slots, another resonant mode can be generated and merged with the first spurious mode, and therefore improve the bandwidth significantly. An antenna prototype was fabricated and measured to validate the design concept. The measured results show that dual-band operation with 10-dB impedance bandwidths of 2.99-3.83 GHz (24.6%) and 5.21-6.89 GHz (27.8%) has been obtained. The antenna has stable broadside and bidirectional radiation patterns with low cross-polarization components over the two operating bands.

2016-05-18 PIER Letters Vol. 60, 59-65, 2016. doi:10.2528/PIERL16032202

Design of Compact Microstrip Antenna Array with Decoupling Network

You-Bao Wang, Shun Xiao, Bo Zhang, and Ye Wei

An innovative decoupling microstrip antenna array is designed. In the design approach, a decoupling and folding microstrip circuit is proposed instead of lumped element circuit, so that the circuit structure is simplified, and the antenna array is fabricated easily in print. Inverted L shape is used as its radiator in order that the size of the antenna array is miniaturized. Stepped impedance transformer is added for the sake of weakening ports reflection. The simulation and measurement results show that the proposed antenna array works at 2.45 GHz, and its reflection coefficient and isolation are both below -20 dB in the working band (2.4 GHz-2.48 GHz). The proposed antenna array has patterns close to omnidirectional.

2016-05-17 PIER Letters Vol. 60, 53-58, 2016. doi:10.2528/PIERL16040601

A Compact Dual-Metal-Plane Highpass Filter Using Hybrid Microstrip/DGS

Hui Chen, Ke-Song Chen, Di Jiang, and Hong-Fei Zhao

A novel and compact highpass filter (HPF) is proposed in this article. This filter is based on a hybrid-coupled dual-metal-plane microstrip/DGS (defected ground structure) on a single-layer substrate. The resonator etched in the grounding plane shows a wide-band dual-mode resonant response within the desired high-pass frequency band, and is composed of a modified U-shaped slot resonator embedded with an L-shaped slot. The wideband highpass filtering performance is achieved by the dual-mode resonator at the bottom of single-layer substrate coupled broadside to the top microstrip stubs. Simulated results from the electromagnetic (EM) analysis software and measured results from a vector network analyzer (VNA) show a good agreement, and an excellent performance with nearly 40 dB attenuation at the lower stopband has also been obtained across an ultra-wide highpass range. A designed and fabricated prototype filter, having a 3-dB cutoff frequency (fc) of 5.9 GHz, shows an ultra-wide highpass range, i.e., from 5.9 to 15.52 GHz, and exhibits the highest pass-band frequency up to 2.6fc. The printed circuit board (PCB) area of the implemented filter is approximately 0.086λg×0.13λg, λg being the guided wavelength at fc.

2016-05-13 PIER Letters Vol. 60, 45-51, 2016. doi:10.2528/PIERL16033003

Analysis of Wide Band Scattering from Objects Using the Adaptive Improved Ultra-Wide Band Characteristic Basis Functions

Wen-Yan Nie and Zhong-Gen Wang

The improved ultra-wide band characteristic basis function method (IUCBFM) is an efficient approach to analyze the wide-band scattering problems because the improved ultra-wide characteristic basis functions (IUCBFs) can be reused for any frequency sample in the range of interest. However, the number of the IUCBFs constructed at the highest frequency point is excessive, and the computational complexity will be increased when applying the same number of IUCBFs at the lower frequency points. To mitigate this problem, an adaptive IUCBFs construction method is presented which can decrease the computational complexity at the lower frequency points. In the proposed method, the given frequency band is adaptively divided into multiple sub-bands in consideration of the number of the IUCBFs. The adaptive IUCBFs are obtained at the highest frequency point in each sub-band, which leads to smaller number of IUCBFs and significant reduction of solver time at lower frequency band. The numerical results have demonstrated the accuracy and efficiency of the proposed method.

2016-05-12 PIER Letters Vol. 60, 39-44, 2016. doi:10.2528/PIERL16030902

Estimating Termination Effect on Electric and Magnetic Field-to-Line Coupling for Radiated Immunity Tests Using a TEM Cell

Chunlei Shi, Changchun Chai, Yintang Yang, and Wenxiao Fang

An analytic model of the field-to-line coupling in time domain for electrically small lines using a transverse electromagnetic (TEM) cell is proposed in this paper. This model uses mutual capacitance and mutual inductance to represent electric and magnetic field couplings which can be obtained based on voltage and current dividers. The measurement and calculation results validate the accuracy of the model. The termination effect on electromagnetic interference (EMI) responses and the separation of electric and magnetic field couplings are investigated by the model. The results indicate relevant suppressions for radiated immunity. This model is convenient for fast radiated immunity estimations.

2016-05-12 PIER Letters Vol. 60, 31-38, 2016. doi:10.2528/PIERL16021107

Low-Profile and Small Capacitively Fed VHF Antenna

Yaakoub Taachouche, Franck Colombel, Mohamed Himdi, and Antoine Guenin

A low profile, compact antenna operating around 162 MHz with omnidirectional vertically polarized radiation is proposed. The antenna is a short monopole capacitively coupled to short-end quarter-wavelength printed line optimized at 162 MHz for Automatic Identification System (AIS) application. The antenna dimensions are less than λ/185 in height and λ/20 in lateral dimension, and the small size of antenna provides a narrow band of 0.34% and gain of -11.6 dBi. The simulated and measured results are in good agreement.

2016-05-11 PIER Letters Vol. 60, 23-30, 2016. doi:10.2528/PIERL16011001

Design of Multi-Stage Power Divider Based on the Theory of Small Reflections

Tongfei Yu, Dongping Liu, Zhiping Li, and Jungang Miao

This paper presents a novel multi-way multi-stage power divider design method based on the theory of small reflections. Firstly, the application of the theory of small reflections is extended from transmission line to microwave network. Secondly, an explicit closed-form analytical formula of the input reflection coefficient, which consists of the scattering parameters of power divider elements and the lengths of interconnection lines between each elements, is derived. Thirdly, the proposed formula is applied to determine the lengths of interconnection lines. A prototype of a 16-way 4-stage power divider working at 4 GHz is designed and fabricated. Both the simulation and measurement results demonstrate the validity of the proposed method.

2016-05-11 PIER Letters Vol. 60, 17-21, 2016. doi:10.2528/PIERL16031005

A Broadband GCPW to Stripline Vertical Transition in LTCC

Bo Zhang, Dong Li, Weihong Liu, and Lin Du

Vertical transition structure between grounded coplanar waveguide (GCPW) and stripline by Low Temperature Co-fired Ceramic (LTCC) technology is presented in this paper. In this structure, the top ground of the stripline is used as the GCPW lower ground, while the signal via goes through the middle ground plane. With increasing vertical signal via height, it can be more widely used in the higher height of multilayer System in Package (SiP) module packaging. The circular openings in the ground plane and additional shield vias around the transmission lines can provide great advantage in the radiation loss and decrease parasitic effects. The measurement results show that the return loss is less than -10 dB from 6 GHz to 35 GHz. Meanwhile, the insertion loss is better than -2 dB up to 28.4 GHz.

2016-04-28 PIER Letters Vol. 60, 9-16, 2016. doi:10.2528/PIERL16032204

A Very Wideband Dipole-Loop Composite Patch Antenna with Simple Feed

Kai He, Peng Fei, and Shu-Xi Gong

By combining a horizontal bowtie electric dipole and a vertical rhombic loop antenna which is realized by a pair of folded shorted patches, a very wideband dipole-loop composite patch antenna is designed. Four tuning stubs are attached to the edges of the bowtie dipole to improve the impedance matching. The bowtie dipole and the rhombic loop antenna are excited simultaneously by a simple feed structure which not only forms a folded balun but also makes the antenna itself be direct current grounded. Results show that a wide impedance bandwidth of 121.6% for |S11|<-10 dB from 3.5 to 14.35 GHz is obtained. Good radiation patterns, low back radiation, low cross polarization level, and a peak antenna gain of 7.7 to 9.8 dBi are achieved over the operating bands.

2016-04-27 PIER Letters Vol. 60, 1-7, 2016. doi:10.2528/PIERL16022701

Broadband Epsilon Negative Transmission Line Resonant Antenna with AIS Loading

Liang-Yuan Liu and Bing-Zhong Wang

A metamaterial-based broadband antenna loaded with artificial impedance surface (AIS) is presented in this letter. Two metallic vias connect a Y-shaped patch to the ground plane. The patch, two metallic vias, and the AIS compose an epsilon negative (ENG) transmission line (TL). The asymmetry Y shaped patch and the AIS bring about the first-order resonance (FOR) and second-order resonance (SOR) modes, which can be merged into one passband to yield a wideband property. The proposed ENG-TL resonant antenna has the advantages of compact size, wide bandwidth, and high gain, which can be applied to portable and handheld communication system.