bluuebunny/crossref_metadata_2025_split huggingface dataset:
V‐Band Push‐Push VCO using Slow‐Wave CPW Resonators for Low Phase Noise Reduction
Authors: Ke Po‐Yu , Chiu Hsien‐Chin , Huang Fan‐Hsiu , Kao Hsuan‐Ling , Chien Feng‐Tsun 
Published: July 2013

ABSTRACTThis article presents a design for two fully integrated millimeter‐wave V‐band push–push voltage‐controlled oscillators (VCOs) implemented in a 150‐nm pHEMT process is presented. Both use slow‐wave coplanar waveguide (CPW) structure transmission line resonators, instead of a lumped LC tank, to provide an extended output frequency range and relatively low phase noise (PN). A LC tank with and without slow‐wave features is used in the two VCO circuits. The measured results for manufactured chips are compared. The VCO with the slow‐wave feature demonstrates a lower PN of −104.5 dBc/Hz at a 1‐MHz offset frequency. A comparison of the designs with and without a slow‐wave VCO shows that the VCO design with slow wave demonstrates lower average PN of approximately 8 dBc at an offset frequency of 1 MHz. Varactor adjustment of the oscillation frequencies for the two VCOs gives 53.2 to 57.1 GHz for the VCO without slow wave and 53.8 to 55.4 GHz for the VCO with slow wave. The two VCOs are developed for use in licensed V‐band transceiver systems. © 2013 Wiley Periodicals, Inc. Microwave Opt Technol Lett 55:2373–2377, 2013
Miniaturized Microstrip Ring Hybrid with Defected Microstrip Structure
Authors: Salari Mohammad Ali , Manoochehri Omid , Abbasiniazare Seyyedpayam 
Published: July 2013

ABSTRACTA method for miniaturization of microstrip rat‐race hybrid with the aid of “defected microstrip structure (DMS)” is proposed. Each transmission line section is loaded with cascaded DMS sections. This results in slow‐wave characteristics which in turn increases the electrical length of the line. In the frequency range below the bandgap, the phase of S21 is negative and DMS behaves as a slow wave device; allowing a miniaturized structure. A reduction of 50% in the occupied area of the circuit and no bandwidth reduction is achieved using this technique. The miniaturized rat‐race operates at 3.4 GHz and can be used in LTE systems. The circuits are fabricated and the measured and simulated results are in excellent agreement. © 2013 Wiley Periodicals, Inc. Microwave Opt Technol Lett 55:2245–2248, 2013
Loop‐Tree Free Augmented Equivalence Principle Algorithm for Low‐Frequency Problems
Authors: Ma Zu‐Hui , Jiang Li Jun , Chew Weng Cho 
Published: July 2013

ABSTRACTIn this article, we describe a newly developed integral equation domain decomposition method for solving complex low frequency electromagnetic problems. This method is based on low frequency augmented equivalence principle algorithm (EPA) with the augmented electric field integral equation (A‐EFIE). The A‐EFIE provides a stable solution in the low‐frequency regime as it includes both charge and current as unknowns to avoid the imbalance between the vector potential and the scalar potential. Based on similar idea, the augmented EPA can suppress the projection error resulting from low‐frequency problems of the normal EPA. Combining these two methods, the proposed algorithm can be used in domain decomposition problems and is numerically stable at low frequencies. Several numerical examples are provided to verify its validity. © 2013 Wiley Periodicals, Inc. Microwave Opt Technol Lett 55:2475–2479, 2013
Distributed Systems Robust to Hand Loading Based on Nonresonant Elements
Authors: Andujar Aurora , Anguera Jaume , Cobo Yolanda 
Published: July 2013

ABSTRACTMiniature and multiband internal antenna systems are strongly required in emergent multifunction wireless devices. Recent techniques are focused on properly exciting ground plane radiation modes through nonresonant elements. These solutions remove the need of including quarter‐wavelength resonant antennas featured by a considerable size. Nevertheless, in this new scenario, the complexity moves toward not only the reduction of the size of the elements used to excite the ground plane mode but also to the simplification of the radiofrequency system used to attain impedance matching. This article proposes the use of distributed systems based on nonresonant elements for solving the bandwidth and efficiency limitations of previous solutions while adding robustness to hand loading effects. Two different feeding schemes, an in‐phase and an out‐of‐phase feeding scheme are simulated, measured, and compared in free‐space as well as regarding the presence of a phantom hand. The proposal provides octo‐band operation and attains a radiating system robust to hand loading effects capable of properly operating in nine communication standards, LTE700, GSM850, GSM900, DCS, PCS, UMTS, LTE2100, LTE2300, and LTE2500. © 2013 Wiley Periodicals, Inc. Microwave Opt Technol Lett 55:2307–2317, 2013
A 3.1–10.6‐GHz Current‐Reused CMOS Ultra‐Wideband Low‐Noise Amplifier Using Self‐Forward Body Bias and Forward Combining Techniques
Authors: Wu Chia‐Hsing , Lin Yo‐Sheng , Wang Chien‐Chin 
Published: July 2013

ABSTRACTA 3.1–10.6‐GHz ultra‐wideband low‐noise amplifier (UWB LNA) with excellent phase linearity property (group‐delay variation is only ±19.46 ps across the whole band) using standard 0.18‐µm CMOS technology is reported. Current reused, self‐forward body bias and forward combining techniques are used to achieve low power and high‐power gain (S21). Both high and flat S21 and low and flat noise figure (NF) frequency responses are achieved by tuning the pole frequencies and pole quality factors of the second‐order gain and NF frequency responses to approximate the maximally flat condition simultaneously. The LNA dissipates 6.93‐mW power and achieves NF of 3.76 at 10 GHz. In addition, the LNA achieves input return loss (S11) smaller than −10.6 dB, and high and flat S21 of 11.02 ± 0.47 dB over the 3.1–10.6‐GHz band. The corresponding figure of merit (FOM) is 3.11 GHz/mW, one of the lowest FOMs ever reported for a 3.1–10.6 GHz CMOS UWB LNA. The measured input third‐order intermodulation point (IIP3) is −3.6 dBm at 6 GHz. © 2013 Wiley Periodicals, Inc. Microwave Opt Technol Lett 55:2296–2302, 2013
Broadband Printed Directional Bow‐Tie Antenna for the 500–1600‐MHz Band
Authors: Cacciatori Alessio , Modotto Daniele , Boscolo Stefano , Midrio Michele , Locatelli Andrea , De Angelis Costantino , Kovács‐Vajna Zsolt M. 
Published: July 2013

ABSTRACTA bow‐tie antenna, suitable for through‐wall radars working in the 500–1600‐MHz band, is designed, fabricated, and measured. The proposed printed antenna and its ground plane based reflector can be readily integrated in a circuit board. A thorough characterization of the prototype confirms the numerically calculated radiation patterns. © 2013 Wiley Periodicals, Inc. Microwave Opt Technol Lett 55:2329–2333, 2013
Graphene in Layered Medium Applications
Authors: Simsek Ergun 
Published: July 2013

ABSTRACTGraphene can be defined either as an infinitely thin material with an optical conductivity or as a thin layer with a finite thickness and an effective complex electrical permittivity. Layered medium Green's functions are calculated according to these two definitions for multilayered structures including a graphene layer. It is found that numerical methods show a good agreement especially in the far field. Moreover, finite thickness method requires significantly less computation time than the effective complex permittivity method. Thus, considering the computation time and accuracy, the finite thickness approach is a better alternative to analyze the electromagnetic wave propagation and scattering in multilayered media with a graphene layer. © 2013 Wiley Periodicals, Inc. Microwave Opt Technol Lett 55:2293–2296, 2013
Phase‐Locked Homodyne Measurement of Quasiprobability Q Function and Detection of Information‐Carrying Weak‐Coherent States
Authors: Garcia Edith , Mendieta Francisco J. , Lopez Josue A. , Alvarez Eduardo , Arvizu Arturo , Gallion Philippe 
Published: July 2013

ABSTRACTWe present an eight‐port homodyne receiver implemented in free space technology for detection of weak coherent states that carry binary information. For transmitted power economy, we use suppressed‐carrier modulation, therefore, we have implemented an optical Costas‐loop‐type carrier synchronizer. We obtain the quasiprobability Q function from the in‐phase and quadrature observables that are simultaneously measured. Statistical results for the quadrature components are presented. We perform measurements for the bit error rate and the mutual information between transmitter–receiver. The results show that the proposed setup is suitable in quantum communications and continuous variable quantum key distribution systems. © 2013 Wiley Periodicals, Inc. Microwave Opt Technol Lett 55:2431–2437, 2013
Compact and High Selectivity Cross‐Coupled Broadband Microstrip Bandpass Filter
Authors: Deng Hong‐wei , Zhao Yong‐jiu , Fu Yong , He Ying , Gao Si‐ping 
Published: July 2013

ABSTRACTIn this article, a new compact and high selectivity broadband microstrip bandpass filter (BPF) is proposed using one folded half‐wavelength resonator (FHWR) in the middle and two quarter‐wavelength resonators (QWRs). Due to the cross coupling between the source/load and FHWR, four transmission zeros can be created in the lower‐ and upper‐stopband. The transmission zero generated by the coupling between the QWR and parallel‐coupling feedline can sharpen the skirt and suppress the first harmonic of the FHWR. To verify the design concept, a microstrip BPF with 1‐dB fractional bandwidth (FBW) of 61% centered at 3 GHz is designed and fabricated. Measured results show low insertion loss and flat group delay in the entire passband as well as high out‐band rejection. © 2013 Wiley Periodicals, Inc. Microwave Opt Technol Lett 55:2501–2504, 2013
Small Size Antenna Based on Metamaterial Split‐Ring Resonators
Authors: Jimenez‐Guzman Gabriel Angel , Tirado‐Mendez Jose Alfredo , Pena‐Rivero Raul 
Published: July 2013

ABSTRACTIn this work, a reduced size planarized antenna based on metamaterial split‐ring resonators (SRRs), for personal communications, is presented. The antenna is based on different size concentric SRRs that operates in the R band, centered at 2.3 GHz. The antenna area is about 15 × 25 mm2, approximately. The measured antenna gain is around −3 dB, with an omnidirectional pattern, and the measured bandwidth is about 1 GHz. © 2013 Wiley Periodicals, Inc. Microwave Opt Technol Lett 55:2345–2350, 2013
Compact Slot Antenna for Mimo Applications in the Wlan Bands
Authors: Naser‐Moghadasi M. , Danideh A. , Bakhtiari A. , Sadeghifakhr R. 
Published: July 2013

ABSTRACTA rectangular slot antenna fed by a coplanar waveguide is proposed for dual‐band wireless local area network (WLAN) operations. The measured −10‐dB bandwidth for return loss is from 2.1 to 2.95 GHz and 5.05 to 6.25 GHz, covering all the 2.4/5‐GHz WLAN bands. A multifeed four‐element planar array was designed and simulated. It shows that the features of small size, uniplanar structure, good radiation characteristics, and small mutual coupling are promising for multi‐input multi‐output applications. © 2013 Wiley Periodicals, Inc. Microwave Opt Technol Lett 55:2490–2493, 2013
Compact Double Band‐Notched Antenna with Nonequiwidth W‐Shaped Slot and “6”‐Shaped Resonance Loop for UWB Applications
Authors: Yang Tang , Song Gao Jin , Song Wang Yan , Guo Feng Xiao 
Published: July 2013

ABSTRACTIn this article, a novel compact double band‐notched antenna with nonequiwidth W‐shaped slot and “6”‐shaped resonance loop on the two sides of the feed line is proposed, which consists of a cone‐shaped monopole patch with nonequiwidth W‐shaped slot and “6”‐shaped resonance loop on the two sides of the feed line, the metal earth‐plate with step slot is designed on other side of the substrate. The simulated and experimental results demonstrate that the proposed antenna can obtain the double band‐notched feature within the bandwidth of 3.3–3.8 GHz and 5.0–6.0 GHz, the impedance bandwidth can achieve from 2.4 to 11.6 GHz (VSWR < 2),which is more than 131%. © 2013 Wiley Periodicals, Inc. Microwave Opt Technol Lett 55:2405–2410, 2013
A Compact ACS‐FED Dual‐Band Meandered Monopole Antenna for Wlan and WiMax Applications
Authors: Li Yingsong , Li Wenxing , Mittra Raj 
Published: July 2013

ABSTRACTIn this article, we present the design of a dual‐band (3.5 and 5.8 GHz), meandered monopole antenna for Wireless Local Area Network (WLAN)/Worldwide Interoperability for Microwave Access (WiMAX) applications, which is fed by an asymmetric coplanar strip (ACS). The proposed antenna is comprised of an asymmetric ground plane, an ACS‐fed structure, and coupled meandered monopole‐type of radiating elements that are designed to provide the two desired operation bands, namely 3.5 and 5.8 GHz. The two resonance frequencies of the antenna can be controlled by adjusting the dimensions of the radiating elements, namely the two meandered monopoles, and the gap between them which controls the coupling. The designed antenna has a small size, which is only 20 × 12 mm2 including the ground plane. Simulated and measured results are presented to demonstrate that the proposed dual‐band antenna is well suited for WLAN and WiMAX applications. © 2013 Wiley Periodicals, Inc. Microwave Opt Technol Lett 55:2370–2373, 2013
An Approach for Determining Equivalent Circuit Model of On‐Chip Inductors
Authors: Yan Na , Yang Chen , Gao Jianjun 
Published: July 2013

ABSTRACTA parameter‐extraction approach for the spiral on‐chip inductors, which combines the analytical approach and the empirical optimization procedure, is developed in this article. The model parameters determined from the analytical expressions are considered as an initial guess of a subsequent optimization procedure leading to the final model parameters. Scaling rule for the inductances of spiral on‐chip inductors has been developed, and very useful for predicting the performance of the on‐chip inductors with larger size. Good agreement is obtained between simulated and measured results for the spiral inductors with different size on silicon in the frequency range of 500 MHz–40 GHz. © 2013 Wiley Periodicals, Inc. Microwave Opt Technol Lett 55:2363–2370, 2013
Prediction of Transmission Path Loss in Indoor Environments with The Radiosity Method
Authors: Mouhtaropoulos Dimitris , Boursianis Achilles , Samaras Theodoros 
Published: July 2013

ABSTRACTIn this work, we present the implementation of the radiosity method for path loss prediction inside indoor environments. We demonstrate its accuracy and computational efficiency by comparing our calculations to the results obtained with measurements and a full wave solution. © 2013 Wiley Periodicals, Inc. Microwave Opt Technol Lett 55:2401–2405, 2013
Multiresonance Monopole Antenna with Band‐Stop Performance
Authors: Ojaroudi Mohammad , Ojaroudi Nasser , Ghadimi Noradin 
Published: July 2013

ABSTRACTIn this article, we present an ultrawideband (UWB) monopole antenna with band‐stop performance. By cutting a vertical rectangular slot in the ground plane and also by inserting a pair of horizontal rectangular slots extra resonances at higher frequencies can be achieved and provide a wide usable fractional bandwidth of more than 150%. A pair of Γ‐shaped strips protruded in the square radiating patch, were applied to generate a band‐notched performance in wireless local area network (WLAN) frequency range. The presented monopole antenna can operate from 2.74 to 16.02 GHz with VSWR < 2, and with a rejection band around of 4.96 to 5.91 GHz to avoid interferences from WLAN Communication systems. Simulated and experimental results obtained for the proposed antenna is suitable for UWB applications. Compact size, wide bandwidth and omnidirectional radiation pattern are of the other features of this antenna. © 2013 Wiley Periodicals, Inc. Microwave Opt Technol Lett 55:2398–2401, 2013
Reduction of Mutual Coupling Between PIFA Antennas for Dual‐Band WiMAX Operations
Authors: Zhai Huiqing , Ma Zhihui , Li Zhenhua , Liang Changhong 
Published: July 2013

ABSTRACTIn this article, a simple and efficient approach is proposed to reduce the mutual coupling between two dual‐band planar inverted‐F antennas. The present isolation structures including one defected ground structure and two “F”‐type strips are introduced to effectively reduce the mutual coupling for two worldwide interoperability for microwave access/2.5 GHz/3.5 GHz bands. By the present method, at least 6 dB reductions of mutual couplings for the two working frequency bands have been obtained, which are verified by measurement results. © 2013 Wiley Periodicals, Inc. Microwave Opt Technol Lett 55:2321–2324, 2013
Study on Curved Wedge Diffraction in NURBS‐UTD Method
Authors: Wang Nan , Dang Xiao‐jie , Yuan Hao‐bo , Liang Chang‐Hong 
Published: July 2013

ABSTRACTThe curved wedge diffraction in nonuniform rational b‐spline (NURBS)‐uniform geometrical theory of diffraction method is studied in this article. The curved wedge is denoted as a NURBS curve while it is also treated as the intersection of two NURBS surfaces. Basic aspects are managed through numerical measures, and parameters used in the calculation of ray field are achieved by using the mathematic definition of NURBS and basic knowledge of differential geometry. Good results are achieved in the examples given and with the contribution of the wedge diffracted ray field to the total ray field, the computational accuracy can be slightly improved. Numerical results show the validation and the improvement. © 2013 Wiley Periodicals, Inc. Microwave Opt Technol Lett 55:2317–2321, 2013
Theoretical and Experimental Studies on Characteristics of An Equilateral Triangular Patch Antenna with and Without Variable Air Gaps
Authors: Biswas Manotosh , Dam Mihir 
Published: July 2013

ABSTRACTIn this article, we present a simple, fast, and accurate CAD oriented cavity model to predict accurately the resonant frequency, input impedance, bandwidth, efficiency, and gain of an equilateral triangular patch antenna with and without air gap in between substrate and ground plane. The present model shows very close agreement with the previously reported experiments for a wide range of antenna parameters and feed locations compared to the other models. The experimental values of input impedance, bandwidth, efficiency, and gain with air gap are not available in open literature. So, we have performed a set of experiments to validate the present model with air gap. The present model without air gap for different substrate parameters are also validated with our own experiments. The accuracy of the present model is calculated with respect to the HFSS computation and experimental results. This model will be very useful for designing the MIC on semiconductor materials with εr > 10 and directly applied in portable wireless equipments. © 2013 Wiley Periodicals, Inc. Microwave Opt Technol Lett 55:2271–2277, 2013
Novel Ultra‐Wideband Filter Using Coplanar‐Waveguide‐To‐Microstrip Transition and Stubs
Authors: Sun Xiaofeng , Tan Eng Leong 
Published: July 2013

ABSTRACTThis letter presents a novel ultra‐wideband (UWB) filter using coplanar‐waveguide (CPW)‐to‐microstrip transition and stubs. The proposed filter is implemented by the CPW series stubs and microstrip shunt stubs. The transition includes a via that not only connects the series and shunt stubs but also can improve the out‐of‐band rejection. The proposed filter has been analyzed, verified, and fabricated. Both simulation and measurement results demonstrate the higher rejection cutoff frequencies above 18 GHz. © 2013 Wiley Periodicals, Inc. Microwave Opt Technol Lett 55:2269–2271, 2013
A Compact Dual‐Passband Filter Using Stepped‐Impedance Resonators
Authors: Tsai Lin‐Chuan 
Published: July 2013

ABSTRACTIn this letter, a new coupling configuration of the stepped‐impedance resonator (SIR) has been presented to design dual‐passband filters with the small circuit size. We design the filter with higher selectivity based on SIR direct‐coupling, input, and output external quality factors. Through resonance characteristics of a SIR, the second resonant frequency can be tuned by adjusting structure parameters. The agreement between measured results and full‐wave simulation prediction validates the feasible configuration of the proposed filters. © 2013 Wiley Periodicals, Inc. Microwave Opt Technol Lett 55:2514–2517, 2013
Design of an Integrated Lens for Separating Microwave and Optical Wave
Authors: Che Rongrong , Yi Zixuan , Zhu Qi , Xin Hao 
Published: July 2013

ABSTRACTIn this article, we proposed a design of an integrated lens, which is composed of an optical Fresnel lens (OFL) and a microwave Fresnel zone plate lens (MFZPL). The MFZPL is constructed by a helices array. The OFL focuses the light wave whereas the MFZPL focuses microwave. Both, simulations and experimental results show that microwave and light wave can be converged in their respective focal regions. © 2013 Wiley Periodicals, Inc. Microwave Opt Technol Lett 55:2358–2363, 2013
Design of a Ka‐Band Microstrip Antenna Array with Sharped‐Beam Pattern and High Gain
Authors: Wu Yiwei , Zhu Qi 
Published: July 2013

ABSTRACTA Ka‐band microstrip array antenna is presented in this article. It operates at 35.1 GHz and can realize sharped‐beam pattern and high gain. The antenna array consisting of 14 ×8 elements is fabricated on Rogers RT5880 substrate with 0.254‐mm thickness. It is center‐fed by a coax probe, and the symmetrical feed network is two‐stage cascaded with unequal amplitudes and the same phase. The total size of the array is 110 ×67 mm2. The simulated and test results show that the antenna array has a gain of 25 dB, the 3 dB beamwidths in azimuth, and elevation plane are less than 6° and 10° respectively, the sub lobe suppression is −18 dB. © 2013 Wiley Periodicals, Inc. Microwave Opt Technol Lett 55:2517–2520, 2013
All‐Fiber Dual‐Wavelength Thulium–Bismuth Codoped Fiber Laser
Authors: Saidin N. , Zen D. I. M. , Damanhuri S. S. A. , Harun S. W. , Ahmad H. , Dimyati K. , Halder A. , Paul M. C. , Pal M. , Bhadra S. K. 
Published: July 2013

ABSTRACTWe report a room temperature all‐fiber dual‐wavelength Thulium–Bismuth codoped fiber laser operating in 1900 nm region using a single fiber Bragg grating (FBG) in a ring configuration. The addition of Bismuth ions as codopant in the gain medium enhances the inhomogeneous broadening effect in the fiber and thus allows a dual‐wavelength oscillation with the assistance of the FBG that has a flat top reflection spectrum. By pumping the gain medium with 1552 nm laser, a dual‐wavelength output lines are obtained at 1901.09 and 1901.98 nm with a spacing of 0.89 nm and an optical signal to noise ratio of more than 45 dB as the polarization controller (PC) orientation is adjusted to balance the loss between the two wavelengths. The dual‐wavelength laser can also be switched to operate in single‐wavelength at either 1901.07 or 1901.98 nm by altering the intracavity polarization using the PC. © 2013 Wiley Periodicals, Inc. Microwave Opt Technol Lett 55:2324–2326, 2013