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oe1(光电查) - 科学论文

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出版时间
  • 2018
研究主题
  • circularly polarized (CP) antenna
  • Elliptical microstrip antenna (EPMA)
  • impedance bandwidth (IBW)
  • defected ground (DG) technique
  • multi-layered stacked structure
  • axial ratio bandwidth (ARBW)
应用领域
  • Optoelectronic Information Science and Engineering
机构单位
  • Bhagwant University, Ajmer, Rajasthan, India
  • Govt Mahila Engineering College, Ajmer, Rajasthan, India
97 条数据
?? 中文（中国） ▾

  • A new dual C-shaped rectangular dielectric resonator based antenna for wideband circularly polarized radiation

    摘要： This article presents a new dual C-shaped rectangular dielectric resonator (DR) based antenna for generation of wideband circularly polarized (CP) radiation. The proposed antenna comprises of a pair of C-shaped rectangular dielectric DR and a metal strip with a coaxial probe. By utilization of a metal strip at the side surface of C-shaped rectangular DR, the wideband CP radiation is achieved from the proposed dielectric resonator antenna (DRA). Fundamental orthogonal modes (TEx δ11 and TEy 1δ1) are excited using the rectangular DRA with a metal strip for the generation of CP fields. The proposed antenna with dual C-shaped rectangular CP DRA provides the measured ?10 dB reflection coefficient bandwidth of 30.07% (3.22 GHz-4.36 GHz) with measured 3-dB axial ratio bandwidth of 14.81% (3.25 GHz-3.77 GHz) at the boresight. The proposed antenna covers the useful Wi-MAX band.

    关键词： wideband,dielectric resonator antenna,coaxial probe,circularly polarized

    更新于2025-09-23 15:23:52

  • A dual-band circularly polarized microstrip patch antenna with a cross shaped slot for 0.92/2.45 GHz RFID applications

    摘要： A double-band circularly polarized (CP) patch antenna is presented. It is a round patch antenna with a cross-shape slot. Furthermore, it radiates wide beam CP waves at two radio-frequency identification (RFID) bands: 920 MHz and 2.45 GHz. Slightly oblate round patch antennas generally radiate CP waves and have resonant frequencies at two or more harmonic bands. To radiate wide beam CP waves at two bands, a cross-shape slot was made on a round patch antenna in this study. As a result, the cross-shape slot has made it possible for a 920 MHz round patch antenna to simultaneously radiate wide beam CP waves at 2.45 GHz which is higher than a harmonic frequency.

    关键词： circularly polarized,RFID,cross shaped slot,double-band,patch antenna

    更新于2025-09-23 15:23:52

  • Control of Circularly Polarized Luminescence by Orientation of Stacked π-Electron Systems

    摘要： New planar chiral building blocks based on 4,7,12,15-tetrasubstituted [2.2]paracyclophanes were obtained via a synthetic route involving an optical resolution step. Planar chiral enantiomers, comprising of two fluorophores that were stacked to form a V-shaped higher-ordered structure, were synthesized from these building blocks. The V-shaped molecules emitted intense circularly polarized luminescence (CPL). Their chiroptical properties were compared with those of X-shaped molecules bearing the same two fluorophores stacked together. CPL sign of the X-shaped molecule was opposite to that of the V-shaped molecule, which is supported by the theoretical results, indicating that CPL sign can be controlled by the orientation of the stacked fluorophores.

    关键词： circularly polarized luminescence,planar chirality,higher-ordered structure,[2.2]paracyclophane

    更新于2025-09-23 15:23:52

  • [IEEE 2018 12th International Conference on Communications (COMM) - Bucharest (2018.6.14-2018.6.16)] 2018 International Conference on Communications (COMM) - Circularly Polarized Array Antenna with Emphasis on the Reduction of RCS by Utilizing Semi-Fractal Elements

    摘要： In this paper, a unique broadband circularly polarized (CP) array antenna by modified feed network is presented. Employing wide band CP semi-fractal aperture coupled structure causes the creation of innovation at CP antenna array with emphasis on reducing of radar cross section (RCS). The 3 dB axial-ratio of the array extends to approximately 1.23 GHz with an impedance bandwidth of 24.77%. An acceptable agreement between the simulation and measured results validates the proposed design.

    关键词： semi-fractal,feed network,Circularly Polarized,RCS

    更新于2025-09-23 15:23:52

  • Circularly Polarized Luminescence from Chiral Conjugated Poly(carbazole-ran-acridine)s with Aggregation-Induced Emission and Delayed Fluorescence

    摘要： Pure organic materials with circularly polarized luminescence (CPL) and delayed fluorescence have gained increasing interest from academic and technological areas. To enhance the solid-state emission and exciton utilization in chiral optoelectronic devices, a synthetic strategy to impart conjugated polymers with CPL and aggregation-induced delayed fluorescence was proposed. Herein, two conjugated macromolecules with electron-donating poly(carbazole-ran-acridine) backbones, electron-withdrawing dibenzothiophen-2-yl(phenyl)methanone and chiral alanine moieties were designed and synthesized. Their neat films exhibited strong green emission with quantum yields of 6.7% and 10.3% and delayed fluorescence with lifetime of 1.358 μs and 1.366 μs, respectively. Both Cotton effect and CPL with dissymmetry factor of –2.01 × 10–3 and –1.39 × 10–3 were determined in the solid state. Such unique conjugated polymers were employed as solution-processed emitting layers in organic light emitting diodes, which displayed maximum brightness of 1477 cd/m2 and maximum current efficiency of 2.52 cd/A.

    关键词： OLEDs,conjugated polymers,aggregation-induced emission,delayed fluorescence,aggregation-induced delayed fluorescence,circularly polarized luminescence

    更新于2025-09-23 15:23:52

  • [IEEE 2018 International Conference on Microwave and Millimeter Wave Technology (ICMMT) - Chengdu, China (2018.5.7-2018.5.11)] 2018 International Conference on Microwave and Millimeter Wave Technology (ICMMT) - A Compact Circularly Polarized Implantable Antenna for Wireless Medical Telemetry

    摘要： A novel miniaturized circularly polarized (CP) patch antenna operating at 915MHz ISM band is designed in this work for wireless biomedical communication. By taking advantage of loading stubs, the proposed antenna features a good miniaturization with the compact size of 13.88×13.88×1.27mm3. A pair of truncated corners in diagonal directions of the planar patch are used for the generation of circular polarization. The simulated 3-dB axial-ratio(AR) bandwidths of around 16MHz is achieved for the proposed antenna, while the impedance bandwidth is 47MHz for |S11| less than -10 dB.

    关键词： miniaturization,Circularly polarized (CP),implantable antenna

    更新于2025-09-23 15:23:52

  • [Institution of Engineering and Technology 12th European Conference on Antennas and Propagation (EuCAP 2018) - London, UK (9-13 April 2018)] 12th European Conference on Antennas and Propagation (EuCAP 2018) - Compact L/S-Band Circularly Polarized Microstrip Antenna over Reactive Impedance Surface

    摘要： A compact LIS-band circularly polarized (CP) antenna over the reactive impedance surface (RIS) is designed, fabricated, and measured. This dual-band CP antenna is excited by two probes and fed by two grounded coplanar waveguides. The CP radiation with very compact antenna size is achieved by stacking a square ring slotted truncated corner square patch and a truncated corner square patch over the RIS. The measured results show that the 3-dB axial ratio bandwidth of the antenna is 0.9% (1.787-1.803 GHz) for the lower band and 1.1% (2.685-2.715 GHz) for the upper band, while the 10-dB return loss bandwidth is 5.9% (1.746-1.852 GHz) and 7.3% (2.586-2.784 GHz), respectively. The antenna gain at boresight is 1.9 dBic for the lower band, and 1.94 dBic for the upper band. The overall volume of the dual-band CP antenna is 0.235 x 0.235 x 0.042λ at 1.765 GHz.

    关键词： reactive impedance surface,circularly polarized antenna,size miniaturization,dual band

    更新于2025-09-23 15:22:29

  • [IEEE 2018 International Conference on Microwave and Millimeter Wave Technology (ICMMT) - Chengdu, China (2018.5.7-2018.5.11)] 2018 International Conference on Microwave and Millimeter Wave Technology (ICMMT) - A Compact Omnidirectional Circularly Polarized Antenna for 5G Communication System

    摘要： In this paper, a compact omnidirectional circularly polarized antenna for 5G communication system is proposed. The design concept is the combination of vertical currents and a surrounding loop current. A center disk-loaded feeding pin and four plated vias are utilized to generate the vertical component of the electric field. While a square loop is employed to produce the horizontal component. Simulation results indicates that the overlapped impedance and AR bandwidth ranges from 27.3 to 28.6 GHz, which covers the 27.5-28.35 GHz band for 5G cellular communication systems. Good omnidirectional radiation patterns can be obtained in azimuthal plane.

    关键词： compact antenna,Circularly polarized (CP),5G communication

    更新于2025-09-23 15:22:29

  • [IEEE 2018 IEEE International Conference on RFID Technology & Application (RFID-TA) - Macau, Macao (2018.9.26-2018.9.28)] 2018 IEEE International Conference on RFID Technology & Application (RFID-TA) - A Wideband Circularly Polarized Patch Antenna Using λ/4 and λ/2 Resonators

    摘要： A wideband circularly polarized (CP) patch antenna with enhanced axial ratio (AR) bandwidth via co-design of feeding network is proposed in this paper. One λ/4 resonator and one λ/2 resonator are introduced and coupled in proximity to two orthogonal points of a square patch radiator to excite two orthogonal modes. These two resonators not only function as impedance matching elements to achieve equal magnitude of two orthogonal modes in a wide frequency band, but also provide the required 90° phase difference. In this way, two minima in the AR response appear, resulting in extended AR bandwidth. Simulated results demonstrate that 2% 3-dB AR bandwidth is achieved on a low profile of 0.014 λ0.

    关键词： wideband,circularly polarized,λ/4 and λ/2 resonators

    更新于2025-09-23 15:22:29

  • Simple Design Procedure of a Broadband Circularly Polarized Slot Monopole Antenna Assisted by Characteristic Mode Analysis

    摘要： In this paper, a systematic design procedure of a compact and broadband circularly polarized (CP) antenna is proposed. The antenna is first designed with a C-shaped monopole, and then a C-shaped slotted patch is utilized to produce CP radiation in the lower frequency band. Thus, the antenna's overall CP bandwidth (BW) is significantly increased. In addition, unlike the conventional method in which the operation is verified by the simulated surface current distribution, characteristic mode analysis (CMA) is carried out to give more insight into different modes on the antenna and generation of circular polarization. The CMA also helps to realize a structural optimization and identify an efficient feed location. The optimized antenna prototype with a compact size of 0.29λo × 0.29λo × 0.01λo (λo is the minimum wavelength at the minimum operation frequency) achieves a usable 10-dB reflection coefficient and 3-dB axial ratio fractional BW of 91% (2.1–5.6 GHz). The antenna realized broadside gain varies from 1.5 to 3.2 dBic within this measured overlapped BW.

    关键词： UWB antenna,slot,circularly polarized (CP),monopole,characteristic mode (CM)

    更新于2025-09-23 15:22:29