bluuebunny/crossref_metadata_2025_split huggingface dataset:
High‐selectivity dual‐band bandpass filter using folded stepped‐impedance resonators and asymmetric coupling lines
Authors: Cheng Wei , Wang Xin‐Huai , Tuo Yong , Bai Yan‐Fu , Shi Xiao‐Wei 
Published: May 2012

AbstractA compact microstrip line dual‐band bandpass filter using folded stepped‐impedance resonators (FSIRs) with high selectivity is proposed and implemented. The filter consists of two FSIRs and asymmetric coupling input/output lines. By utilizing resonance characteristics of the FSIRs, a compact filter is designed for WLAN (2.4 and 5.2 GHz). In the new design, asymmetric coupling input/output lines are applied not only to generate two more transmission zeros than the symmetric ones but also to tune the transmission zeros to improve the selectivity. These performances are demonstrated by simulation and measurement. Owing to asymmetric coupling input/output lines, five transmission zeros could be generated near the passband edges to improve the selectivity. Both experimental and simulated results are with good agreement. © 2012 Wiley Periodicals, Inc. Microwave Opt Technol Lett 54:1866–1869, 2012; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.26928
Comment on “Experimental study of electromagnetic band gaps using plasmas as defaults in a metallic photonic crystal”
Authors: Jha Ratneshwar 
Published: May 2012

AbstractOriginal article published Microwave Opt Technol Lett 53:1109–1113, 2011. © 2012 Wiley Periodicals, Inc. Microwave Opt Technol Lett 54:2006, 2012; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.26929
Compact conventional phone antenna integrated with wideband multiple‐input‐multiple‐output antenna
Authors: Li Jian‐Feng , Chu Qing‐Xin , Li Zhi‐Hui 
Published: May 2012

AbstractA compact conventional phone antenna integrated with wideband multiple‐input‐multiple‐output (MIMO) antenna is presented.Within operation band of the MIMO antenna, the effect of mutual coupling between the conventional phone antenna and the MIMO antenna is reduced by etching three slits into the ground plane, and this slits also can relieve the impedance matching degradation caused by the mutual coupling between the conventional phone antenna and the MIMO antenna. A wideband T‐shaped neutralization line without effect on the performance of conventional phone antenna is applied to enhance the isolation for the two MIMO antenna elements. Therefore, high isolation is achieved within the operation band of the MIMO antenna. The two operation bands of the convention phone antenna with VSWR ≤ 3 are 0.89–0.96 GHz and 1.71–2.18 GHz, respectively, and the operation band of the MIMO antenna with VSWR ≤ 1.7 and isolation ≥ 20 dB is 2.4–3.7 GHz. Moreover, the conventional phone antenna has good omnidirectional radiation patterns in H‐plane, and the MIMO antenna has back‐radiation patterns for diversity gain. © 2012 Wiley Periodicals, Inc. Microwave Opt Technol Lett 54:1958–1962, 2012; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.26930
Thermally tunable metamaterial based on thermochromic effect
Authors: Huang Jinguo , Xuan Yimin , Li Qiang 
Published: May 2012

AbstractA composite structure is proposed by combining a thermochromic oxide with a fishnet structure, which is a metamaterial with tunable negative refractive index that is clearly observed for some special wavelength band for the proposed structure. The negative refractive index is attributed to the excitation of internal surface plasmonic polaritons. The spectral negative refractive index can be self‐regulated with the temperature, which is of significant importance to extend the applications of negative index materials. It is also demonstrated that the wavelength region with negative refractive index can be designed to locate at desired position by dexterously tailoring the structural parameters. © 2012 Wiley Periodicals, Inc. Microwave Opt Technol Lett 54:1889–1893, 2012; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.26931
Low‐cost microstrip filter antenna with a monopole‐like radiation pattern for RF front end
Authors: Wu Wei‐Jun , Yin Ying‐Zeng , Xie Jiao‐Jiao , Ren Xue‐Shi , Zuo Shao‐Li 
Published: May 2012

AbstractA low‐cost microstrip filter antenna with a monopole‐like radiation pattern suitable to be embedded inside a RF front end of wireless communication systems is presented. The filter antenna comprises two square open‐loop resonators, a coupled line, and a microstrip antenna with an impedance transformation line. The microstrip antenna is excited by the coupled line, which is treated as the admittance inverter in filter design. The microstrip antenna performs as not only a radiator but also the last resonator of the bandpass filter. Therefore, the transmission loss between the filter and the antenna is reduced. The patch of the microstrip antenna is stacked above the system circuit board of the RF front end. In this case, the design can fully integrate the circuit board of the RF front end into an internal filter‐antenna solution. The design procedure of the filter antenna follows the circuit approach—synthesis of bandpass filters. The measured results show good agreement with the simulated ones. © 2012 Wiley Periodicals, Inc. Microwave Opt Technol Lett 54:1810–1814, 2012; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.26932
Dual‐band microstrip antenna structure combined with high‐gain dielectric rod and sleeve‐dipole elements
Authors: Batgerel Ariunzaya , Eom Soon‐Young 
Published: May 2012

AbstractThis article presents a dual‐resonator antenna where a stacked microstrip patch antenna uses a protruding dielectric rod for high gain, and a sleeve‐dipole antenna to support the rod as well as to resonate at another frequency.The proposed antenna structure could be optimized at any two frequencies. However, we designed the microstrip patch to resonate at 2.44 GHz while the sleeve‐dipole at 0.859 GHz. Main points of designing considerations and electrical performances of a fabricated antenna were briefly discussed. © 2012 Wiley Periodicals, Inc. Microwave Opt Technol Lett 54:1835–1838, 2012; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.26933
A 1–12‐GHz variable‐gain low‐noise amplifier MMIC using 0.25‐μm SiGe BiCMOS technology
Authors: Chang Woojin , Lee Sang‐Heung , Mun Jae‐Kyoung , Nam Eunsoo 
Published: May 2012

AbstractThis article introduces an 1–12‐GHz differential two‐stage variable‐gain low‐noise amplifier (VGLNA) using 0.25‐μm SiGe:C BiCMOS commercial process technology for ultra‐wideband system.The results of the fabricated monolithic microwave integrated circuit amplifier show 18‐dB gain with a 3‐dB frequency band of 1.3–11.9 GHz and noise figure of less than 5 dB under the bias condition of 2.5‐V supply voltage and 55‐mW total dc power consumption. The gain‐control range is from −17 dB to +18 dB. The chip size of the manufactured VGLNA is 1.1 × 0.9 mm2 including all testing pads for RF and dc probes. © 2012 Wiley Periodicals, Inc. Microwave Opt Technol Lett 54:1935–1937, 2012; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.26936
Estimation of coupling parameters for auto‐motorized fabrication of fused fiber coupler
Authors: Irawan Dedi , Saktioto  , Ali Jalil , Fadhali Mohamed , Erwin  
Published: May 2012

AbstractA directional fiber coupler with exertion loss 0.03 dB has been successfully fabricated using fusion technique with typical coupling ratio 1–90%. The coupling region of two twisted single mode fiber is heated by injecting hydrogen gas at 2.5 bar. During fusion process, both two sides of fibers are pulled by stages that are automatically motorized in range of 800–4800 μm, and stopped when the desired coupling ratio is reached. The parameters of automated mechanical motion of pulling stages and coupling parameters at fusion region have been calculated by using kinetic model. The effect of heating and elongation reduces the diameter of cross section tapered region with a diameter 6.35 micrometer scale. As the fabrication of fiber couplers described by degree of fusion, which is function of heating and pulling length, it can be seen clearly that the coupling coefficient between the fibers increases exponentially with increasing the degree of fusion. However, by knowing coupling power and mechanical motion parameters, the fabrication of directional fiber coupler can be optimized. © 2012 Wiley Periodicals, Inc. Microwave Opt Technol Lett 54:1932–1935, 2012; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.26937
Meander line‐loaded planar monopole antennas
Authors: Elsheakh Dalia M. , E. Safwat Amr M. 
Published: May 2012

AbstractTwo‐dimensional meander line‐loaded monopole antennas are presented in this article. They provide either multibands or ultrawideband (UWB). For multiband antenna, the total area is 58 × 60 mm2 and it covers the following bands: 0.9, 1.85, 2.1, 2.5, 3.5, and 5.2 GHz. The UWB antenna is achieved by connecting in parallel four meander line‐loaded monopoles with different lengths. Its total area is 150 × 80 mm2 and the obtained bandwidth extends from 0.9 to 10 GHz. The antennas are matched to a 50‐Ω line feed without the need for an external matching network. © 2012 Wiley Periodicals, Inc. Microwave Opt Technol Lett 54:1851–1854, 2012; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.26939
Novel dual‐mode patch band‐pass filters with slit structures
Authors: La Dong‐sheng , Ma Xue‐lian , Wu Ya‐ping 
Published: May 2012

AbstractNovel microstrip band‐pass filters using dual‐node patch resonators with slit structures are proposed and optimized in this article.By using etched slit defected structures in the square patch resonator and in the circle patch resonator, the filters have remarkable advantages, such as compact size, high selectivity, and simple structure. The proposed band‐pass filters are fabricated and measured. The measured results prove to be largely consistent with the simulated results. © 2012 Wiley Periodicals, Inc. Microwave Opt Technol Lett 54:1965–1968, 2012; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.26941
High efficiency and suppression harmonics oscillator using front coupled tapered CMRC
Authors: Hayati Mohsen , Lotfi Ali 
Published: May 2012

AbstractThis article presents a novel terminating network for microwave transistor oscillator.A front coupled tapered compact microstrip resonant cell (FCTCMRC) is inserted between the transistor and the input fundamental matching network as its terminating resonance. The fundamental frequency from the output can be connected in a positive feedback loop to the input port by tuning the dimensions of the proposed FCTCMRC. This feedback can simultaneously act as a negative feedback for the second harmonic frequency. The output at the fundamental frequency improved due to the second harmonic suppression. The proposed FCTCMRC is used to obtain as high a reflection coefficient as possible, while providing the oscillation condition with the incorporated microwave transistor. The measured results show 63.05% improvement suppression of the second harmonic using FCTCMRC in comparison with the conventional microstrip line. © 2012 Wiley Periodicals, Inc. Microwave Opt Technol Lett 54:1862–1866, 2012; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.26943
Compact Ultra‐Wideband slot antenna with band‐notch property
Authors: Naser‐Moghadasi M. , Asadpor L. , Virdee B.S. 
Published: May 2012

AbstractA very small and compact ultra‐wideband (UWB) slot antenna is presented, which possesses band‐notch characteristic to eliminate interference signals. The antenna comprises a rectangular aperture (9 × 18 mm2) etched on the ground‐plane of a printed circuit board and a rectangular shaped stub, also total size of the antenna is 19 × 19 mm2. The antenna uses a novel technique comprising of open‐end stubs at the periphery of the ground‐plane in the vicinity of the feed‐line to improve its VSWR performance over the UWB. An effective conductor‐backed plane structure is used to generate the necessary band‐notch characteristic at the WLAN interfering band (5–6 GHz). The antenna exhibits broadband impedance matching with stable and omnidirectional radiation patterns and gain performance despite its very small size across the entire UWB from 3–11 GHz. © 2012 Wiley Periodicals, Inc. Microwave Opt Technol Lett 54:1829–1832, 2012; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.26944
80–110 GHz MMIC amplifiers using a 0.1‐μm GaAs‐based mHEMT technology
Authors: Kang Dong Min , Yoon Hyung Sup 
Published: May 2012

AbstractA 80–110 GHz broadband MMIC low noise amplifiers (LNAs) have been developed for W‐band passive image sensors.A monolithic microwave integrated circuit (MMIC) LNAs consists of a four‐stage single‐ended type and a four‐stage balanced type. The chip set was fabricated using a 0.1‐μm gate‐length InGaAs/InAlAs/GaAs metamorphic high electron mobility transistor process based on a four‐inch substrate. The single‐ended type LNA (ver.1) achieved a gain of 20 dB over in a band between 85 and 105 GHz and a noise figure of lower than 5.3 dB in a frequency range of 86.5–100 GHz. The single‐ended type LNA (ver.2) exhibited a gain of 27 dB with a noise figure of 4.3 dB at 94 GHz. The external DC biasing conditions of Vds and Vgs were 1 and −0.2 V, respectively, and the total current consumption of the LNA was 40 mA. The chip size was 2 × 1.2 mm2. The balanced‐type amplifier demonstrated a measured small signal gain of over 18 dB from 80 to 100 GHz. The external DC biasing conditions of Vds and Vgs were 1 and −0.2 V, respectively, and the total current consumption was 82 mA. The chip size was 2.9 × 2.5 mm2. © 2012 Wiley Periodicals, Inc. Microwave Opt Technol Lett 54:1978–1982, 2012; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.26948
A low‐phase noise and wide‐tuning range CMOS voltage controlled oscillator
Authors: Lin Yao‐Chian , Yeh Mei‐Ling 
Published: May 2012

AbstractA wide‐tuning range and ultra‐low‐phase‐noise 4.28‐GHz voltage controlled oscillator (VCO) is designed in this article. The VCO implemented with the TSMC 0.18 μm 1P6M CMOS technology uses NMOSs only. Source capacitive degeneration technique is used to increase the frequency tuning range. The proposed VCO can have an 18.94% tuning range from 3.53 to 4.34 GHz. The measured phase noise is −131.2 dBc/Hz at 1‐MHz offset from the 4.28 GHz. The corresponding figure‐of‐merit (FOM) and FOMT are calculated to be −191.6 and −197.15 dBc/Hz, respectively. The chip size is 0.571 × 0.822 mm2. The core circuit consumes 16.5‐mW and 1.3‐V power supply. © 2012 Wiley Periodicals, Inc. Microwave Opt Technol Lett 54:1941–1944, 2012; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.26950
Easy fabrication of long‐period fiber grating by winding a wire around an optical fiber fixed to cylindrical ROD
Authors: Lee Cherl‐Hee , Lee Jonghun , Park Jaehee , Taek Kim Kwang 
Published: May 2012

AbstractA new approach is presented for the easy fabrication of wire‐winding long‐period fiber grating based on the periodic winding of a wire around an optical fiber attached to a cylindrical rod. The periodic pressure of the wire induces change of the refractive index of the optical fiber core, and so the resonance wavelengths of the grating can be easily controlled according to the winding‐wire pitch controlled by a microprocessor. At the winding‐wire pitch of 500 μm, the spectra show resonance–wavelength dips corresponding to the LP02, LP03, LP04, and LP05 cladding modes; the resonance wavelengths go to longer wavelengths at the increased winding pitch of 510 μm; these are in good agreement with theoretical values. The polarization dependence of a resonance wavelength shift of 9 nm and transmission power difference of 2.5 dB was shown at the 520 μm grating pitch. When the diameter of the cylindrical metal rod was smaller, or higher tension by the winding pressure was applied, stronger mode coupling resulted in deeper dips in the transmission spectra according to induced higher index variation. © 2012 Wiley Periodicals, Inc. Microwave Opt Technol Lett 54:1937–1941, 2012; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.26951
Dual‐band branch‐line coupler using double‐sided parallel‐strip line
Authors: Lee Jung‐Kyu , Jung Dong‐Jin , Chang Kai 
Published: May 2012

AbstractIn this article, a three branch‐line coupler is proposed for the dual‐band application. The coupler can operate at two arbitrary frequencies and be realized on double‐sided parallel‐strip line (DSPSL). One of the advantages of the DSPSL is easy realization of high impedance transmission line. The circuit design parameters are derived using the even and odd mode analysis. The measured results show a good performance at 3 and 5.77 GHz. © 2012 Wiley Periodicals, Inc. Microwave Opt Technol Lett 54:1898–1900, 2012; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.26952
Synthesis of frequency selective surfaces using genetic algorithm combined with the equivalent circuit method
Authors: Campos A. L. P. S. , Martins A.M. , Almeida Filho V. A. 
Published: May 2012

AbstractGenetic algorithms (GAs) are optimization algorithms that use stochastic techniques inspired in the natural evolution theory. They consist of search algorithms that aim to find a set of parameters that minimizes or maximizes a certain cost function. In this article, the problem is to find a set of physical dimensions for a frequency selective surface (FSS) that force it to have some desired properties. The idea is to use the fact that the analysis of the FSS is much simpler than the synthesis. In this article, this is done for two kinds of FSSs, the square loop and the quasi‐square open loop. Representative numerical examples are presented to demonstrate the effectiveness of the method. Finally, the performance of the GA is presented. © 2012 Wiley Periodicals, Inc. Microwave Opt Technol Lett 54:1893–1897, 2012; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.26953
200‐GHz bandwidth on wafer characterization of CMOS nonlinear transmission line using electro‐optic sampling
Authors: Jamshidifar M. , Spickermann G. , Schäfer H. , Bolivar P. Haring 
Published: May 2012

AbstractA free running electro‐optic sampling system for on wafer characterization of a 65‐nm technology CMOS nonlinear transmission line with the assessment of device performance up to 200 GHz is described. Noise and relative timing jitter between laser and microwave source, as the major limiting factors for the system dynamic range and bandwidth, are studied. Eventually enhancing the system measurement bandwidth using a fast method, and durable against timing jitter, is achieved at the expense of degraded system noise. © 2012 Wiley Periodicals, Inc. Microwave Opt Technol Lett 54:1858–1862, 2012; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.26954
A compact monopole MIMO array for the 5–6‐GHz band
Authors: Pigozzo F. M. , Giltrelli M. , Sacchetto F. , Assalini A. , Capobianco A. D. 
Published: May 2012

AbstractIn this article, a low‐cost compact multiple‐input multiple‐output array composed of three coplanar waveguide‐fed monopoles printed on flame retardant 4 substrate is presented.The particular feeding mechanism of each single element allows for a wideband behavior, and the specific delta (Δ) shape arrangement of the three radiators leads to a remarkably small footprint. The proposed design is capable of operating in the entire 5–6‐GHz spectrum hence resulting particularly attractive for the IEEE 802.11n 5‐GHz standard. A prototype was fabricated and connected to a Ralink 3 × 3 evaluation board to assess the throughput performance in a typical indoor scenario. The effectiveness of the proposed array is confirmed by experimental results. © 2012 Wiley Periodicals, Inc. Microwave Opt Technol Lett 54:1854–1858, 2012; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.26955
A compact tri‐band bandpass filter with adjustable third passband using square open loop resonator embedded by open stubs
Authors: Ma Xing‐Bing , Zheng Hong‐Xing 
Published: May 2012

AbstractTo obtain an adjustable passband filter, some open stubs are embedded into an open loop resonator. The third resonant frequency can be adjusted by changing size of the stub added at the middle. A tri‐band microstrip bandpass filter is designed to verify the proposed topology, and a prototype was fabricated. Measurement results demonstrate that operating frequency of the sample achieves around 0.86, 1.83, and 2.98 GHz. © 2012 Wiley Periodicals, Inc. Microwave Opt Technol Lett 54:1817–1819, 2012; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.26957
Compact circularly polarized asymmetric‐slotted microstrip patch antennas
Authors: Nasimuddin  , Chen Zhi Ning , Qing Xianming 
Published: May 2012

AbstractA technique is demonstrated to generate circularly polarized (CP) radiation of the compact diagonally asymmetric‐slotted microstrip patch antennas. Design rules for the single‐feed, compact, circularly polarized microstrip antennas (CPMA) with any arbitrary‐shaped slots along the diagonal directions are first summarized. Four, compact, CPMA with circular‐, square‐, cross‐, and square‐ring‐shaped slots along the diagonal directions are proposed and compared based on a fixed overall antenna size. A compact, CP, cross‐shaped slotted, microstrip antenna is fabricated and measured to verify the proposed technique experimentally. The measured 3‐dB axial‐ratio bandwidth of about 6.0 MHz is achieved with 10‐dB return loss bandwidth of 19.0 MHz while measured gain of the antenna is 4.0 dBic at 930 MHz. © 2012 Wiley Periodicals, Inc. Microwave Opt Technol Lett 54:1920–1927, 2012; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.26959
Double‐flip trapezium monopole antenna with high gain design using beveling technique
Authors: Jusoh M. , Jamlos M. F. , Kamarudin M. R. 
Published: May 2012

AbstractThis letter presents a compact double‐flip trapezium monopole antenna (D‐FTMA) for ultra wideband (UWB) application. A significant impedance bandwidth improvement of 7:1 can be achieved at a centre frequency of 7.96 GHz compared to the conventional antenna when the dual bevel technique is deployed near the ground plane. The proposed compact antenna consists of 22 mm × 25.8 mm radiating element and 64 mm × 40 mm rectangular ground plane and fed by a 50 Ω coaxial connector. Furthermore, the low cost D‐FTMA is fabricated on the FR4‐PCB. The antenna agrees between simulation and measurement of return loss, which covers the UWB frequency range (3.1–10.6 GHz). The D‐FTMA has a very constant and high relative gain at particular frequency up to 6 dBi. Moreover, the D‐FTMA is observably capable in producing divisive radiation patterns with linear polarization at four different frequencies: 4, 6, 8, and 10 GHz. The parameter optimization analysis has been studied using CST Microwave Studio. The presented simulated results are supported by the measurement as well. © 2012 Wiley Periodicals, Inc. Microwave Opt Technol Lett 54:1882–1886, 2012; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.26960
A wideband linear array with reduced number of antenna elements
Authors: Ren Yu‐Jiun 
Published: May 2012

AbstractAn X‐band linear array antenna with reduced number of elements is presented. To suppress the sidelobe level using fewer array elements, the synthesis of a nonuniform antenna array has been implemented with the matrix pencil method (MPM) that can provide the excitation and location distribution to miniaturize the array dimension. A comparison with the conventional array antennas with uniform and conventional distributions is conducted to demonstrate the performance of the proposed wideband array, which also experimentally verifies the feasibility of the MPM. The developed array antenna is suitable for portable devices, mini mobile platforms, and low‐tier unmanned vehicles. © 2012 Wiley Periodicals, Inc. Microwave Opt Technol Lett 54:1846–1848, 2012; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.26962