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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） ▾

  • [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) - An Implantable Circularly Polarized Patch Antenna for Pacemaker Monitoring System

    摘要： In this study, a single-fed circularly polarized (CP) patch antenna working at 1.23 GHz is presented and realized. The quality factor of patch antenna is driven by its input impedance. The proposed patch antenna is properly combined with an actual pacemaker for enhancement of its radiation performance. Another patch antenna with miniaturized size is designed, fabricated, and tested. The simulated results are found in good agreement with its measured one.

    关键词： radiation performance,circularly polarized,pacemaker,input impedance,miniaturized size,patch antenna,quality factor

    更新于2025-09-19 17:15:36

  • [IEEE 2018 18th Mediterranean Microwave Symposium (MMS) - Istanbul, Turkey (2018.10.31-2018.11.2)] 2018 18th Mediterranean Microwave Symposium (MMS) - Miniaturized and Circularly Polarized Inverted C Shaped Patch Antenna for X and Ku Bands Applications

    摘要： This paper presents a miniaturized inverted C shaped patch antenna with defected ground structure (DGS), which exhibits an axial ratio bandwidth (ARBW) of 1.1 GHz (from 11.79 GHz to 12.89 GHz) within an impedance bandwidth (IBW) of 6.9 GHz (from 9.1 GHz to 16 GHz), with a maximum realized gain of 3.23 dBi. The antenna size is only 15x10x1.524 mm3. These features make the proposed antenna the best candidate for compactness wireless applications such as radar, satellite communications, and wireless computer networks.

    关键词： circularly polarized patch antenna,patch antennas,defected ground structure (DGS),Miniaturized patch antenna

    更新于2025-09-19 17:15:36

  • A Circularly-Polarized Differentially-Fed Transmission-Line-Excited Magneto-Electric Dipole Antenna Array for 5G Applications

    摘要： A differentially-fed circularly-polarized magneto-electric dipole (ME-dipole) array is proposed for 5G applications. The proposed transmission-line-excited (TLE) antenna, fabricated on a printed-circuit-board (PCB), can achieve wide impedance and axial ratio (AR) bandwidths and high gain. The antenna consists of a 2×2 ME-dipole array enclosed by a circular cavity. It is modified from our previous work on linearly-polarized (LP) array with its element orientation selectively rotated by ±45o with respect to the differentially-fed transmission line and the use of sequential rotation technique (SRT) to generate circularly-polarized (CP) radiation. A differential feed network is utilized to feed the prototype for experiments. Experiments show that the antenna can present an overlapping impedance and AR bandwidth of 32.2% from 52.2 to 72.2 GHz with a broadside left-handed CP (LHCP) gain from 10.2 to 11.8 dBic. The proposed CP antenna retains all the salient features of our previously proposed linearly-polarized (LP) antenna in symmetric and stable radiation patterns and relatively low back radiation levels.

    关键词： fifth generation (5G),Circularly-polarized (CP),magneto-electric dipole (ME-dipole),differential feed

    更新于2025-09-19 17:15:36

  • [IEEE 2018 Asia-Pacific Microwave Conference (APMC) - Kyoto, Japan (2018.11.6-2018.11.9)] 2018 Asia-Pacific Microwave Conference (APMC) - A Low-Profile and High-Gain Circularly Polarized Antenna Based on Holographic Principle

    摘要： This paper presents a low-profile and high-gain right circularly polarized antenna based on holographic artificial impedance surface. The holographic antenna (HA) is comprised of around 2000 various elements printed on grounded dielectric substrate, excited by a horizontally omnidirectional ring-slot antenna. By using anisotropic rectangle patch as unit cell, the cross polarization is suppressed and the cross-polar level is of -37.8 dB in broadside. The -10 dB impedance bandwith covers 9 GHz to 11 GHz and the 3-dB axial ratio bandwith covers 9.12 GHz to 11 GHz. The maximum right circularly polarized gain is 20.8 dB and the 3-dB beamwidth is 6.08° at 20 GHz. The simulated results show the proposed antenna possesses low-profile, high-gain, and narrow pencil beam in the operating band.

    关键词： circularly polarized,high-gain,low-profile,holographic antenna

    更新于2025-09-19 17:15:36

  • Self-Assembled Nanohelix for White Circularly Polarized Luminescence via Chirality and Energy Transfer

    摘要： Chiral nanostructures and their optical activity have been attracting great interest. Here, we designed enantiomer bolaamphiphile containing a naphthalene moiety (bola-1) and alkyl spacer, and investigated their self-assembly as well as optical activity. It was found the compound could form gels in various organic or mixed organic/water mixtures. In mixed DMSO/water, it formed nanohelix. Due to the fluorescent nature of the naphthyl group, the nanohelix showed both CD and circularly polarized luminescence (CPL). When three achiral fluorescent molecules, pyrene-1-carboxylic acid (D2), rhodamine 110 (D3) and rhodamine B (D4), were incorporated into the helical structures formed by bola-1, the nanohelix could be remained and the CPL from the dye molecules could be induced. In addition, an energy transfer occurred between the bola-1 nanohelix and the dyes. By mixing the different emission dyes with the bola-1 in an appropriated ratio, a white CPL was obtained. It was found the dissymmetry factor of the white CPL could be increased through the energy transfer. This work provided a new convenient and efficient way of fabricating while CPL.

    关键词： nanohelix,white CPL,circularly polarized luminescence,energy transfer,optical activity,Chiral nanostructures,bolaamphiphile

    更新于2025-09-19 17:13:59

  • Preorganized helical chirality controlled homochiral self-assembly and circularly polarized luminescence in a quadruple-stranded Eu2L4 helicate

    摘要： The homochiral quadruple-stranded helicate, ΔΔ-(Eu2L4) assembled from the bis-β-diketone with the preorganized helical chirality shows strong circularly polarized luminescence.

    关键词： preorganized helical chirality,circularly polarized luminescence,homochiral,bis-β-diketone,quadruple-stranded helicate

    更新于2025-09-19 17:13:59

  • in a circularly polarized laser pulse

    摘要： The dissociation of H2 + in a circularly polarized laser pulse is numerically studied by simulating the time-dependent Schr?dinger equation. After absorbing one or three photons, the nuclear wave packets carrying the angular momenta ˉh and 3 ˉh dissociate along the 2pσu state. Due to the broad initial kinetic-energy distribution of the superimposed nuclear vibrational states, the one-photon and three-photon dissociation pathways may end with the same kinetic energy. These coexisting dissociation pathways with same parities but different orbital angular momenta interfere with each other, resulting in the spiral nuclear momentum distribution in the laser polarization plane. The interference structure in the nuclear momentum distribution offers another freedom to identify the dissociation pathways of molecules in strong laser fields.

    关键词： time-dependent Schr?dinger equation,photon dissociation pathways,circularly polarized laser pulse,spiral nuclear momentum distribution,H2 + dissociation

    更新于2025-09-19 17:13:59

  • Photoinduced Chirality Switching of Metal-Inorganic Plasmonic Nanostructures

    摘要： Chiral plasmonic nanodevices whose handedness can be switched reversibly between right and left by external stimulation have attracted much attention. However, they require delicate DNA nanostructures and/or continuous external stimulation. In this study, those issues are addressed by using metal-inorganic nanostructures and photoinduced reversible redox reactions at the nanostructures, namely site-selective oxidation due to plasmon-induced charge separation (PICS) under circularly polarized visible light (CPL) and reduction by UV-induced TiO2 photocatalysis. We irradiate gold nanorods (AuNRs) supported on TiO2 with right- or left-CPL to generate electric fields with chiral distribution around each AuNR, and to deposit PbO2 at the sites where the electric fields are localized, for fixing the chirality to the AuNR. The nanostructures thus prepared exhibit circular dichroism (CD) based on longitudinal and transverse plasmon modes of the AuNRs. Their chirality given by right-CPL (or left-CPL) is locked until PbO2 is re-reduced under UV light. After unlocking by UV, the chirality can be switched by left-CPL (or right-CPL) irradiation, resulting in reversed CD signals and locking the switch again. The handedness of the chiral plasmonic nanodevice can be switched reversibly and repeatedly.

    关键词： plasmon-induced charge separation,circular dichroism,chiral plasmonic nanodevice,nanofabrication,circularly polarized light

    更新于2025-09-19 17:13:59

  • Absorption and opacity threshold for a thin foil in a strong circularly polarized laser field

    摘要： We show that a commonly accepted transparency threshold for a thin foil in a strong circularly polarized normally incident laser pulse needs a refinement. We present an analytical model that correctly accounts for laser absorption. The refined threshold is determined not solely by the laser amplitude, but by other parameters that are equally or even more important. Our predictions are in perfect agreement with particle-in-cell simulations. The refined criterion is crucial for configuring laser plasma experiments in the high-field domain. In addition, an opaque foil steepens the pulse front, which can be important for numerous applications.

    关键词： particle-in-cell simulations,transparency threshold,circularly polarized laser field,laser absorption,thin foil

    更新于2025-09-19 17:13:59

  • Substrate integrated waveguide dual‐frequency dual‐sense circularly polarized cavity‐backed slot antenna

    摘要： A novel design of dual-frequency dual-sense circularly polarized (CP) substrate integrated waveguide (SIW) cavity-backed slot antenna is presented for dual-band wireless communication systems. The proposed antenna consists of square SIW cavity, asymmetrical bow-tie-shaped cross slot and probe feed. Due to use of asymmetrical bow-tie-shaped cross slot, circularly polarized wave radiates at two different frequencies with opposite sense of polarizations. The RHCP radiation occurs at (10.45-10.54) GHz (Lower band) and LHCP occurs at (11.26-11.34) GHz (Upper band). Moreover, in each band, sense of polarization can be change by changing the feed position. The front to back radiation ratio (FTBRR) is more than 10.5 dB and cross polarization level is lower than ?20 dB in both the bands.

    关键词： dual-frequency dual-sense,bow-tie-shaped cross slot,circularly polarized,square SIW cavity

    更新于2025-09-19 17:13:59