bluuebunny/crossref_metadata_2025_split huggingface dataset:
AN e‐shaped slotted‐circular‐patch antenna for circularly polarized radiation and radiofrequency energy harvesting
Authors: Bernard Loo B.K. , Nasimuddin  , Alphones A. 
Published: February 2016

ABSTRACTAn e‐shaped slotted‐circular‐patch antenna is proposed for circularly polarized (CP) radiation and RF energy harvesting. The proposed antenna consists of an e‐shaped slotted‐circular‐patch radiator and a coaxial feed. An e‐shaped slot is cut along the orthogonal axis of a circular‐patch with a coaxial feed along the diagonal axis to generate CP radiation with compact antenna size of 45 × 45 × 1.6 mm. The prototype antenna shows the measured gain more than 5 dBic at 2.4 GHz with 3 dB axial ratio beamwidth more than 140°. © 2016 Wiley Periodicals, Inc. Microwave Opt Technol Lett 58:868–875, 2016
Modeling of two‐pump optical frequency comb generation in monolithic silicon nitride ring resonator
Authors: Wang Rui 
Published: February 2016

ABSTRACTThe two‐pump Four‐Wave‐Mixing (FWM) in the ring resonator promises more agile compact frequency comb generation than the traditional singe‐pump scheme regarding the convenient tuning of comb line space by modifying the two pumps’ space. The silicon‐nitride‐ring‐resonator‐based optical frequency comb generation system input with two pumps for the parametric process is simulated by an iterative process relying on the split‐step Fourier method. The influences of the coupling coefficient and pumps’ frequencies on the comb spanning are explained in terms of Q factor and resonance condition of the ring. © 2016 Wiley Periodicals, Inc. Microwave Opt Technol Lett 58:919–921, 2016
Bandpass filter based on novel‐coupled half‐wavelength microstrip ring resonators
Authors: Olokede Seyi S. , Zubir Ihsan A. , Ain Mohd F. , Ahmad Zainal A. 
Published: February 2016

ABSTRACTA microstrip bandpass filter (BPF) based on centre‐coupled cylindrical microstrip ring resonator (MRR) for wireless application in ISM frequency band of applications is presented. The proposed is a combination of two identical bended half‐wavelength (λ/2) MRR, and centre‐coupled by an end‐coupled transmission feed line. The equivalent circuits of the MRR, the end‐coupled feed, and the effects of various spacing between them were investigated based on the even‐ and odd‐mode theory. The mechanism of resonant mode splitting is investigated with the possibility of enhancing the coupling effect, while suppressing spurious resonances in order to achieve sharp rejection skirts. Findings indicates that the proposed equivalent circuit are influenced by capacitances due to resonator – transmission feed line gap (d), the gap between each ring (g), the feed line gap (i), the radius of MRR (r), and the resonator head (m). The operation mechanism of the structure was investigated first theoretically to the intent of design a circuit model, then using numerical 3D EM based on finite integration technique (FIT) method, and finally, through 2D equivalent circuit modeller. The derived equivalent circuit model have been validated both by analytical formulae and numerical simulations. © 2016 Wiley Periodicals, Inc. Microwave Opt Technol Lett 58:911–918, 2016
Extremely wideband printed monopole antenna with dual rejection bands
Authors: Amiri Zhale , Movagharnia Sima , Masoumi Masoume , Shokry Majed , Virdee Bal S. 
Published: February 2016

ABSTRACTAn extremely wideband (EWB) microstrip antenna is presented that is designed with band rejection characteristics at C and WLAN bands. This is achieved by embedding inside the inverted triangular shaped patch a pair of L‐shaped slits that have been rotated by ±90° so that they are horizontal and downward facing, and topping the patch with an arrow‐shaped strip. The feedline to the patch also needs to be backed with a trapezoid shaped ground‐plane. The center frequency of the notched bands can be easily controlled by altering the parameters of the slits and arrow‐shaped strip. The low‐profile antenna essentially radiates omni‐directionally and has a measured impedance bandwidth of 18.9 GHz (2.9–21.8 GHz) with a VSWR ≤ 2, except at the two rejection bands. The antenna has an average gain > 3 dBi. © 2016 Wiley Periodicals, Inc. Microwave Opt Technol Lett 58:908–911, 2016
Low‐cost antenna design for RFID readers using multiobjective optimization
Authors: Oliveira Diogo B. , Lisboa Adriano C. , Fonseca Leandro A. C. , Silva Elson. J. , Adriano Ricardo 
Published: February 2016

ABSTRACTThis article presents a systematic methodology to aid design a low‐cost patch antenna for RFID readers. The geometric antenna parameters are found using multiobjective optimization for return loss minimization and gain maximization. To assess the use of low‐cost FR‐4 substrate the radiation efficiency has been investigated using software simulations. A prototype antenna was built and its parameters were measured in the anechoic chamber. © 2016 Wiley Periodicals, Inc. Microwave Opt Technol Lett 58:905–908, 2016
A suspended stripline bandpass filter using hybrid transmission line stepped impedance resonator
Authors: Xu ZhaoXu , Hu YiYao , Chen Yongpin P. , Kang Kai , Le Wei Li Joshua 
Published: February 2016

ABSTRACTIn this article, a suspended stripline bandpass filter using hybrid transmission line stepped impedance resonator (HTLSIR) is proposed. SSL has been proven to be an excellent transmission‐line system for realizing different types of filters. However, due to the effective permittivity being too close to unity, the size of the distributed elements is usually very large. The novel resonator introduced in this letter contains a section of hybrid transmission line which consists of the SSL and the microstrip line. The characteristics of the HTLSIR have been analyzed clearly. The novel SSL filter is designed, fabricated, and tested. Both simulated and measured results are presented. © 2016 Wiley Periodicals, Inc. Microwave Opt Technol Lett 58:892–895, 2016
Small‐size narrow open‐slot antenna for the 2.4/5.2/5.8‐GHz WLAN operation along the side edge of the metal‐framed smartphone
Authors: Wong Kin‐Lu , Lu Jun‐Yu 
Published: February 2016

ABSTRACTA small‐size narrow open‐slot antenna with 1‐mm slot width and 12.7‐mm slot length promising to be disposed in the narrow region along the side edge of the metal‐framed smartphone for the 2.4/5.2/5.8‐GHz WLAN operation is presented. This study exploits the narrow region between the display panel and the casing of the metal‐framed smartphone to dispose the internal antenna therein. The proposed antenna is fed using a microstrip feedline with its tuning stub disposed within the slot, thereby keeping narrow width of the antenna. The open slot (denoted as a first slot) has a 1‐mm opening disposed at the metal frame, and its length corresponds to only about 0.1 wavelength at 2450 MHz, which supports a fundamental open‐slot mode to cover the 2.4 GHz band. In addition, with a chip capacitor (1.1 pF) loaded at a proper position across the first slot, the antenna can be reconfigured at about 5.2 GHz to create a new resonant open slot (second slot) from the capacitor to the slot opening. This second slot contributes to a new resonant mode for the antenna to cover the 5.2 GHz band. By embedding a series chip inductor (1.5 nH) in the microstrip feedline, a higher‐order slot mode supported by the first slot can be shifted to cover the 5.8 GHz band. The antenna can hence cover the 2.4/5.2/5.8‐GHz WLAN operation with a compact and narrow slot structure. Details of the proposed antenna are described. © 2016 Wiley Periodicals, Inc. Microwave Opt Technol Lett 58:886–892, 2016
A 3–7 GHz GaNHEMT power amplifier
Authors: Cheng Zhiqun , Zhu Dandan , Yan Guoguo , Liu Guohua , Gao Steven 
Published: February 2016

ABSTRACTAn ultra‐broadband power amplifier (PA) with TGF2023‐2‐10 GaN HEMT operating in the frequency of 3–7 GHz is presented in this article. The GaN HEMT transistor is modeled and the frequency compensation and multi impedance matching approach with different characteristic impedances of transmission line are employed for broadband impedance matching. The measured results agree well with the simulated results. The PA has output power of more than 41.2 dBm and small‐signal gain of 8 dB at the frequency range of 3–7 GHz under DC bias of Vds = 28 V, Vgs = −2.98 V. Details of device modeling, amplifier designs, and simulated and measured results are presented and discussed. © 2016 Wiley Periodicals, Inc. Microwave Opt Technol Lett 58:901–904, 2016
Realization of all‐optical logic gates using injection locking in a distributed feedback laser diode
Authors: Qureshi Khurram K. 
Published: February 2016

ABSTRACTIn this article, we experimentally demonstrate an all‐optical inverter and NOR logic working at 10 Gbit/s using injection locking technique in a Distributed Feedback laser diode. The proposed optical inverter operate at 10 Gb/s with very good extinction ratio of around 15 dB with a power penalty of only 2 dB at BER of 10−9. © 2016 Wiley Periodicals, Inc. Microwave Opt Technol Lett 58:940–944, 2016
Metamaterial inspired monopole antenna for WLAN/WiMAX applications
Authors: Imaculate Rosaline S. , Raghavan S. 
Published: February 2016

ABSTRACTA compact hexagonal‐shaped split ring radiating monopole with multiple band notched characteristics is presented in this article. The proposed antenna is printed on a 24 × 22.5 × 0.8 mm3 FR‐4 substrate and it operates in the WLAN 2.4/5.2/5.8 GHz bands and WiMAX 3.5 GHz band. It yields an impedance bandwidth of 130 MHz centered at 2.45 GHz, 330 MHz centered at 3.5 GHz, and 1540 MHz centered at 5.2 GHz. The extraction of the effective material parameter of the radiating element is discussed, by which the metamaterial property existence and the notch creation is verified. A prototype of the proposed antenna is fabricated and the results are measured, which agrees greatly with the simulated results. Consistent radiation pattern and stable gain are observed over all the operating regions. © 2016 Wiley Periodicals, Inc. Microwave Opt Technol Lett 58:936–939, 2016
Broadband (22–40 GHz) multistage MMIC low‐noise amplifier
Authors: Gao Xingzhen , Yang Shuang , Gu Jianzhong , Wang Wei , Sun Xiaowei 
Published: February 2016

ABSTRACTIn this article, a wideband (22–40 GHz) four‐stage monolithic microwave integrated circuit low noise amplifier has been presented, which was fabricated in WIN 0.15 um pseudomorphic high electron‐mobility transistor technology. The source inductor and interstage mismatching methods were used to realize both low noise and flatten gain simultaneously in wideband. The designed LNA has achieved a gain of 22 ± 1 dB and a noise figure of less than 3 dB from 22 to 40 GHz. The chip size was 2 × 1 mm2, which can be used in active phased‐array receiver modules, millimeter wave imaging, broadband wireless communication systems, and 24‐GHz short‐range sensors. In addition the LNA was worked with only one supply power, which was realized by four self ‐bias resistances. © 2016 Wiley Periodicals, Inc. Microwave Opt Technol Lett 58:956–959, 2016
Coupled line based unequal dual band power divider
Authors: Yadav Amar Nath , Bhattacharjee Ratnajit 
Published: February 2016

ABSTRACTThis article presents theoretical design of dual band unequal power divider based on coupled line structure. The structure consists of two coupled line segments along with five transmission line segments used to satisfy unequal matching characteristic. The isolation is achieved using a circuit, which is a combination of inductor, capacitor, and resistor. Design equations of proposed power divider and the circuit providing isolation are based on circuit representation of ideal transmission lines. Simulation and measured results are given to verify the theoretical design equations. © 2016 Wiley Periodicals, Inc. Microwave Opt Technol Lett 58:953–956, 2016
A simple transformation from lowpass to bandpass filter using a new quasi‐arrow head defected ground structure resonator and gap‐J‐inverter
Authors: Boutejdar Ahmed , Ellatif W. Abd , Ibrahim A. A. , Challal M. 
Published: February 2016

ABSTRACTIn this article, a new compact quasi‐arrow head defected ground structure (DGS) lowpass filter (LPF) is proposed. The proposed DGS behaves as a resonant element which allows size compactness and harmonic suppression in the rejection band. The proposed LPF presents the advantages of compactness, low insertion loss, and ultrawide stopband with 20 dB attenuation from 6 GHz to >20 GHz. The length of the proposed multilayer LPF is reduced to 0.143 λg at 3 GHz in comparison with 0.2 λg for the cascaded topology with λg = 0.157 m. A novel compact bandpass filter (BPF) is presented by utilizing a simple transformation from LPF based on J‐inverter technique. The proposed BPF has low insertion loss and compact size. Finally, the simulated and experimental results of proposed structure are found to be in good agreement with the simulation results. © 2016 Wiley Periodicals, Inc. Microwave Opt Technol Lett 58:947–953, 2016
Compact double‐layer substrate integrated waveguide magic Tee for X‐band applications
Authors: Venanzoni Giuseppe , Mencarelli Davide , Morini Antonio , Farina Marco , Losito Onofrio , Prudenzano Francesco 
Published: February 2016

ABSTRACTA substrate integrated waveguide Magic Tee with very compact size and operating over a wide band is proposed. The circuit is made of two stacked substrates connected by cutting a small aperture between them. This solution presents slightly higher complexity compared to a single substrate magic Tee but it avoids the radiation losses because the circuit is completely closed. A simple and effective procedure is used to design the circuit. A prototype is built and experimental results show a good agreement with simulations. © 2016 Wiley Periodicals, Inc. Microwave Opt Technol Lett 58:932–936, 2016
Double band microwave rectifier for energy harvesting
Authors: Adam Ismahayati , Fareq Abd Malek Mohd , Najib Mohd Yasin Mohd , Rahim Hasliza A. 
Published: February 2016

ABSTRACTEnergy harvesting has been investigated by many researchers due to their ability to generate power by using existing sources which eliminate the need of batteries and power supply that requires extra cost to the system. Rectifier is the main component in energy harvesting where it converts RF sources to DC power. This work presents the design and investigation of the seven‐stage rectifier. A Villard configuration is chosen with consists of two HSMS 2850 Schottky diodes and two through hole ceramic capacitors for each stage. The aim of this article is to study and evaluate the rectifier performance at 550 MHz and 900 MHz frequency range. Rectifier properties such as number of stage, capacitance effects, and variation in capacitor's combination, and are analyzed and discussed in this article. The result shows that the designed rectifier is operate well at the targeted frequencies. Measured results show that voltages of 9.17 V and 3.78 V are obtained for an input of 0 dBm at 900 MHz and 550 MHz, respectively. The circuit is generating 44.4% rectified output than in the reference work. © 2016 Wiley Periodicals, Inc. Microwave Opt Technol Lett 58:922–927, 2016
Wideband RCS reduction of patch array antenna with miniaturized FSS
Authors: Joozdani Mohsen Zahir , Amirhosseini Mohammad Khalaj , Abdolali Ali 
Published: February 2016

ABSTRACTIn this article, radar cross section reduction of 2 × 2 patch array antenna is investigated using band‐stop Frequency selective surface consisted of miniaturized square loop elements. Stop band of FSS is as the same as the frequency band of antenna resonance which is from 3.3 to 3.4 GHz. Ground plane of conventional patch array antenna is substituted by miniaturized FSS except the regions underneath the patches. FSS acts as the ground plane in the stop‐band and is transparent in the other frequencies. Thus, wideband reduction of RCS is obtained from 4 to 9.5 GHz and changes in antenna pattern, gain, and impedance bandwidth in comparison with the ones of conventional patch array antenna are negligible. It is shown that simulation and measurement results are in good agreement with each other. © 2016 Wiley Periodicals, Inc. Microwave Opt Technol Lett 58:969–973, 2016
Compact CPW UWB diversity slot antenna with dual band‐notched characteristics
Authors: Zhu Jianfeng , Feng Botao , Peng Biao , Li Shufang , Deng Li 
Published: February 2016

ABSTRACTA compact coplanar waveguide (CPW) fed ultrawideband (UWB) slot antenna for multiple‐input‐multiple‐output (MIMO)/diversity applications is presented in this letter. The antenna consists of two coplanar waveguides (CPWs) feeding circular radiating elements and a protruded stub, which is placed at
between them. The circular radiating elements are arrange orthogonally and fed perpendicularly to obtain polarization diversity. Notched band at X‐band communication downlinks is achieved by etching split ring resonator slots in the radiators and the other notched band at WLAN system is achieved by the collaboration of arc‐shaped strips and the protruded stub. The protruded stub not only can help to achieve band rejection but also can reduce mutual coupling between two ports. As all of the structures are printed in one layer, it can be very easily to be integrated with RF front‐end circuits. Simulated and measured results show that the proposed antenna meets the 10‐dB impedance bandwidth from 3.4 to 12 GHz and isolation better than 15 dB at most of the band. Good diversity performance in terms of envelope correlation coefficient and the ratio of mean effective gain demonstrates that the antenna is quite suitable for MIMO UWB applications. © 2016 Wiley Periodicals, Inc. Microwave Opt Technol Lett 58:989–994, 2016
Miniaturized wideband bandstop filter using an air‐bridge capacitor via gallium‐arsenide based integrated passive device technology
Authors: Dhakal Rajendra , Kim Nam‐Young 
Published: February 2016

ABSTRACTThis letter reports a new implementation of miniaturized wideband bandstop (WBBS) filter using a gallium‐arsenide (GaAs)‐based integrated passive device technology (IPD). The implementation of an air‐bridge capacitor explores the possibility of frequency selectivity from 8.15 to 9.20 GHz. The WBBS filter generates a return loss of −0.50 dB with a rejection depth of −38.01 dB at the resonance frequency of 9.20 GHz. The size of the filter was drastically reduced by implementing a microfabrication (IPD) with folded meandered‐line, featuring the length equal to 0.38 times the guided wavelength (λg) that occupies only 0.22 λg × 0.13 λg of the die area. The selectivity of the filter was reflected by the higher value of return loss with sufficient suppression of out‐of‐band signals close to the resonance frequency. Experimental verification of the filter response demonstrates its potential as a WBBS filter operating in the X‐band frequency spectrum. © 2016 Wiley Periodicals, Inc. Microwave Opt Technol Lett 58:980–985, 2016
A sharp skirt notch filter based feedforward 3rd harmonic cancellation scheme for ultra‐high frequency wireless communication system in 834–879 MHz
Authors: Jung Won‐Jae , Jung Jin‐Woo , Jang Peter , Park Jun‐Seok 
Published: February 2016

ABSTRACTThis article presents a feedforward 3rd harmonic cancellation scheme for ultra‐high frequency (UHF) wireless communication system in 834–879 MHz. The major features are highlighted: a special notch filter with sharp skirt performance (e.g., both lower and higher band edge from 834 to 879 MHz yield lower than −40 dB cutoff), and micro‐controller based amplitude/phase control on feedforward path signal generation for fine harmonic cancellation. A prototype was implemented; it works out 47.36 dB Hz−1 cut‐off and 60 dBc ACLR. © 2016 Wiley Periodicals, Inc. Microwave Opt Technol Lett 58:1006–1010, 2016
A novel type of bandpass filter using complementary open‐ring resonator loaded HMSIW with an electric cross‐coupling
Authors: Yan Tengfei , Tang Xiao‐Hong , Xu Zhao‐Xu , Lu Di 
Published: February 2016

ABSTRACTA novel bandpass filter (BPF) with multiple transmission zeros (TZs) and wide stopband is proposed. The filter is realised using complementary open‐ring resonators (CORRs) loaded half mode substrate integrated waveguide (HMSIW). Besides, a novel electric source‐load electric cross‐coupling configuration is introduced to generate extra attenuation poles at either side of the passband, which improves the passband selectivity and the stopband suppression level. Based on this structure, a BPF operating at 5.8 GHz with multiple transmission zeros is designed and fabricated. The Measurement and simulation results indicate that the proposed configuration is a good candidate for filter design. © 2016 Wiley Periodicals, Inc. Microwave Opt Technol Lett 58:998–1001, 2016
Diet‐induced obesity and insulin resistance are associated with brown fat degeneration in SIRT1‐deficient mice
Authors: Xu Fen , Zheng Xiaobin , Lin Beisi , Liang Hua , Cai Mengyin , Cao Huanyi , Ye Jianping , Weng Jianping 
Published: February 2016

ObjectiveRecent studies have revealed that SIRT1 gain‐of‐function could promote adipose tissue browning for the adaptive thermogenesis under normal diet. This study investigated the role of SIRT1 loss‐of‐function in diet‐induced obesity and insulin resistance and the mechanism involved in adipose tissue thermogenesis.MethodsMale SIRT1+/− and wild‐type (WT) mice were fed with a high‐fat diet (HFD) for 16 weeks to induce obesity and insulin resistance, while mice on a chow diet were used as lean controls. The phenotype data were collected, and different adipose tissue depots were used for mechanism research.ResultsCompared with WT mice, SIRT1+/− mice exhibited increased adiposity and more severe insulin resistance with less thermogenesis under HFD challenge. Strikingly, SIRT1+/− mice displayed an exacerbated brown adipose tissue (BAT) degeneration phenotype, which was characterized by lower thermogenic activity, aggravated mitochondrial dysfunction, and more mitochondrial loss. In addition, SIRT1+/− mice showed aggravated inflammation and dysfunction in epididymal adipose tissue after HFD intervention, which also contributed to the systemic insulin resistance.ConclusionsDiet‐induced obesity and insulin resistance are associated with BAT degeneration in SIRT1‐deficient mice, which further underlined the beneficial role of SIRT1 in obesity‐associated metabolic disorders.