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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） ▾

  • STUDY OF MULTI-BAND CIRCULARLY POLARIZED MICROSTRIP ANTENNA WITH COMPACT SIZE

    摘要： In some satellite navigation receiver systems, there is not enough space to settle several antennas for multi-port multi-band application generally. A triple-deck circularly polarized antenna with three ports for receiving and sending satellites signal is studied in this paper. The design idea in this paper is to place several single-feed microstrip antennas layer by layer for saving space. All patch antennas are probe-fed, and the probe connected with the upper patch goes through the clear hole in lower substrates. The structure of the multi-band antenna is investigated thoroughly. How to tune this kind of antenna is a big problem in application, and one special parameter is given to adjust the performance of the antenna. The designed triple-deck antenna works at the bands of GPS, BDS and 1.66 GHz independently. The formal two bands are RHCP, and the third band is LHCP, so it can receive and send signals at the same time. Both simulated and measured results show that all three working bands can cover the system use di?erently. Axial ratio less than 3 dB at center frequency is obtained, and absolute gain at center frequency is more than 4 dBic. The advantages of this antenna are compact in size for multi-port multi-band use and easy fabrication.

    关键词： multi-band,satellite navigation,circularly polarized,compact size,microstrip antenna

    更新于2025-09-09 09:28:46

  • [IEEE 2018 International Conference on Advances in Computing, Communications and Informatics (ICACCI) - Bangalore, India (2018.9.19-2018.9.22)] 2018 International Conference on Advances in Computing, Communications and Informatics (ICACCI) - Design and Analysis of Circularly Polarized Defected Ground Elliptical Patch Antenna for Long Term Evolution (LTE) and 4G Wireless Applications

    摘要： In this article the strategy and analysis of a defected ground stacked elliptical patch microstrip antenna (EPMA) is presented for circular polarization (CP). This antenna gives an impedance bandwidth of 44.0% with respect to resonant frequency 1.98GHz, which is eight times greater in comparision to conventional elliptical patch microstrip antenna (EPMA) along with axial ratio bandwidth of 5.5% with reverence to frequency 1.98GHz. The antenna is studied on a Flame Retardant (FR-4) substrate having substrate permittivity 4.4 and thickness 1.59mm. The CP behaviour is observed by truncating the conventional elliptical patch and inserting slots. A square slot is also etched in ground plane at an angle of 45 degrees with respect to horizontal axis. This antenna design having a dimension of ground plane 35.0×32.0 mm2. To achieve the higher impedance bandwidth, the technique of multilayer stacked of patch is used. The over all height of antenna is 9.18mm. This antenna can be used in Long Term Evolution (LTE) and 4G Wireless Applications.

    关键词： circularly polarized (CP) antenna,Elliptical microstrip antenna (EPMA),impedance bandwidth (IBW),defected ground (DG) technique,multi-layered stacked structure,axial ratio bandwidth (ARBW)

    更新于2025-09-09 09:28:46

  • CPW-FED CIRCULARLY POLARIZED SQUARE SLOT ANTENNA WITH ENHANCED BANDWIDTH AND REDUCED SIZE FOR WIDEBAND WIRELESS APPLICATIONS

    摘要： A coplanar waveguide-fed circularly polarized square slot antenna with the feasibility of obtaining a wider bandwidth and a relatively smaller size is proposed and demonstrated. The proposed antenna, consisting of a stepped feeding strip, a modified grounded L-shaped radiating patch, an inverted-L grounded strip and an asymmetric ground with an L-shaped slot as well as two horizontal slots, is designed, analyzed and fabricated. Good agreement between simulated and measured results is observed. Simulation and measurement results reveal that the proposed antenna can provide an impedance bandwidth of 106.3% (2.3–7.52 GHz) and a 3-dB axial ratio (AR) bandwidth of 90.2% (2.25–5.95 GHz). Additionally, within the effective circular polarization (CP) bandwidth of 88.5% (2.3–5.95 GHz), the proposed antenna has gains from 1.9 dBic to 5.2 dBic with an average gain of 3.9 dBic.

    关键词： Coplanar waveguide-fed,wideband wireless applications,reduced size,square slot antenna,enhanced bandwidth,circularly polarized

    更新于2025-09-09 09:28:46

  • [IEEE 2018 48th European Microwave Conference (EuMC) - Madrid, Spain (2018.9.23-2018.9.27)] 2018 48th European Microwave Conference (EuMC) - Blazed Metasurface Grating with Handedness Preservation for Circularly Polarized Incident Wave

    摘要： A new blazed metasurface grating for circularly polarized (CP) incident wave operating at 10 GHz is proposed. Such a structure can provide strong auto-collimation for the CP incident wave. Unlike the conventional scatterer, which typically reverses the handedness of the incident CP wave upon re?ection, the proposed grating can preserve the handedness. The auto-collimation blazing effect and handedness preservation are achieved by a specially designed reactive impedance surface, which allows independent response controls to transverse electric (TE) and transverse magnetic (TM) polarizations. The proposed idea is demonstrated by simulations and veri?ed by experiments. Comparisons with conventional sawtooth grating are made through measurements.

    关键词： metasurface,circularly polarized wave,Littrow,blazed,auto-collimation,handedness preservation

    更新于2025-09-09 09:28:46

  • A BROADBAND CPW-FED CIRCULARLY POLARIZED SQUARE SLOT ANTENNA FOR UHF RFID APPLICATIONS

    摘要： A broadband CPW-fed circularly polarized square slot antenna for ultra-high-frequency (UHF) radio frequency identification (RFID) applications is proposed. It consists of a square slot embedded with a spur line along diagonal and an F-shaped feeding structure. The proposed antenna achieves an impedance bandwidth about 307 MHz (34.6% @886 MHz) and a 3 dB axial ratio (AR) bandwidth about 232 MHz (24.3% @954 MHz). The 3 dB AR beam-width is about 96 degrees over the UHF band of 840–960 MHz. The proposed reader antenna based on CPW structure is easy to integrate. With the symmetry and bidirectional radiation pattern, there are less readers needed in some applications, such as access control, than the reader with unidirectional pattern, which will definitely decrease the implemented cost. Therefore, this universal design with desired performance across the entire UHF RFID band (from 840 MHz to 960 MHz) can be applied to all the UHF RFID applications worldwide. Detailed considerations of the design and main parameters will be studied in this paper.

    关键词： square slot antenna,UHF RFID,broadband,circularly polarized,CPW-fed

    更新于2025-09-09 09:28:46

  • Determination of Handedness in a Single Chiral Nanocrystal via Circularly Polarized Luminescence

    摘要： The occurrence of biological homochirality is attributed to symmetry breaking mechanisms which are still debatable. Studies of symmetry breaking require tools for monitoring the population ratios of individual chiral nano-objects, such as molecules, polymers or nanocrystals. Moreover, mapping their spatial distributions may elucidate on their symmetry breaking mechanism. While luminescence is preferred for detecting single particle chirality due to its high signal to noise ratio, the typical low optical activity of chromophores limits its applicability. Here, we report on handedness determination of single chiral lanthanide based luminescent nanocrystals with a total photon count of 2×104. Due to the large emission dissymmetry we could determine the handedness of individual particles using only a single circular polarization component of the emission spectrum, without polarization modulation. A machine learning algorithm, trained to several spectral lineshape features, enabled us to determine and spatially map the handedness of individual nanocrystals with high accuracy and speed. This technique may become invaluable in studies of symmetry breaking in chiral materials.

    关键词： chiroptical activity,circularly polarized luminescence,lanthanide nanocrystals,single-particle spectroscopy

    更新于2025-09-09 09:28:46

  • [IEEE 2018 IEEE Asia-Pacific Conference on Antennas and Propagation (APCAP) - Auckland, New Zealand (2018.8.5-2018.8.8)] 2018 IEEE Asia-Pacific Conference on Antennas and Propagation (APCAP) - A Metasurfaced Pyramidal Horn Antenna for Circularly-Polarized Applications

    摘要： A high-gain circularly-polarized pyramidal horn antenna is developed by loading a thin metasurface linear-to-circular polarization (LP-CP) converter on the aperture of a standard pyramidal horn. The LP-CP converter is composed of two identical dielectric slabs, sandwiched by three subwavelength metallic element arrays. By placing the metasurface LP-CP converter on the aperture of a standard horn antenna, the linearly-polarized wave emitted by the horn can be converted to be circularly-polarized, without changing much other radiation performance. An example is given of a metasurface LP-CP converter and horn (metahorn) antenna that exhibits high gain and circular polarization. The measurement of this metahorn shows a 3-dB axial ratio bandwidth of 8.7%, with a maximum gain reduction of 2 dB, compared with that of the original air-filled standard pyramidal horn.

    关键词： pyramidal horn,polarization converter,circularly-polarized,metasurface

    更新于2025-09-09 09:28:46

  • [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 Novel Broadband Low-Profile Planar Circularly Polarized Micro-Strip Mono-Pulse Antenna Array

    摘要： A novel compact micro-strip mono-pulse antenna array is proposed. The antenna unit use L-shaped coupling feed. Then a 4 × 4 planar circularly polarized planar mono-pulse antenna array is made up. A broadband feeding network which is composed of the sum-difference network and four power dividers is designed. The simulation results show that a gain peak value of 19dBic and51.9% of efficiency at 2.2G Hz have been obtained, the 3 dB axial-ratio bandwidth can reach 36% (2.05-2.75GHz), and the impedance bandwidth of the antenna is reach 45% (1.75GHz-2.75GHz), respectively. It fully shows that the two antenna arrays have high gain, wide bandwidth and circular polarization, which proves the validity of the design method.

    关键词： Micro-strip,Sum-difference Network,Mono-pulse,L-shaped coupling,Circularly Polarized

    更新于2025-09-09 09:28:46

  • Wideband and low profile polarization conversion meatasurface-based circularly polarized slot antenna

    摘要： The purpose of this study is to investigate the application of a polarization conversion metasurface for constructing a low profile, wideband circularly polarized slot antenna, which consists of a new Polarization conversion metasurface (PCM)-based square-corner-cut artificial magnetic conductor cell structure and a feeding slot antenna. PCM possesses two frequency points of polarization rotation (PR), produced by appropriately adjusting width between the two triangular metallic patches. A 39.3% (4.7-7 GHz) of big PR band was realized through the combination of two neighboring PR frequency points. The impedance bandwidth of PCM based patch antenna was measured to be 43.5% (4.5-7 GHz), with 17.2% (5.3-6.3 GHz) of 3 dB axial ratio (AR) bandwidth and 0.045λ0 of profile. It also generated 7.3 dBic of high broadside gain in operational bandwidth.

    关键词： PCM,dual-patch,circularly polarized,wideband,low profile

    更新于2025-09-04 15:30:14

  • Photon Upconverted Circularly Polarized Luminescence via Triplet-Triplet Annihilation

    摘要： Circularly polarized luminescent materials are of increasing attention due to their potential applications in advanced optical technologies, such as chiroptical devices and optical sensing. Recently, in all reported circularly polarized luminescent materials, high-energy excitation results in low-energy or downconverted circularly polarized luminescence (CPL) emission. Although photon upconversion—i.e., the conversion of low-energy light into higher-energy emission, with a wide variety of applications—has been widely reported, the integration of photon upconversion and CPL in one chiral system to achieve higher-energy CPL emission has never been reported. Herein, a brief review is provided of recent achievements in photon-upconverted CPL via the triplet–triplet annihilation mechanism, focusing on the amplified dissymmetry factor glum through energy transfer process and dual upconverted and downconverted CPL emission through chirality and energy transfer process.

    关键词： triplet–triplet annihilation,photon upconversion,energy transfer,triplet energy migration,circularly polarized luminescence

    更新于2025-09-04 15:30:14