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oe1(光电查) - 科学论文

127 条数据
?? 中文(中国)
  • Perpendicular-Corporate Feed in a Four-Layer Circularly-Polarized Parallel-Plate Slot Array

    摘要: This paper presents a design for the perpendicular-corporate feed in a four-layer circularly-polarized parallel-plate slot array antenna. We place a dielectric layer with adequate permittivity in the region between the coupling-aperture and the radiating-slot layers to remove x-shaped cavity walls completely in the radiating part of a conventional planar corporate-feed waveguide slot array antenna. To address fabrication constraints, the dielectric layer consists of PTFE and air. It excites a strong standing wave in the region and so provides 2 × 2-element subarrays with uniform excitation. None of the slot layers are in electrical contact due to air gaps between the slot layers. The four-layer structure with apertures for circular polarization contributes to wideband design for axial ratios because of the eigenmodes in the desired band. We realize an 11.9% bandwidth for axial ratios of less than 3.0 dB as confirmed by measurements in the 60 GHz band. At the design frequency, the measured realized gain is 32.7 dBi with an antenna efficiency of 75.5%.

    关键词: slot array,perpendicular-corporate feed,circularly-polarization,parallel plates

    更新于2025-09-23 15:22:29

  • Improvement of the Beam-Wave Interaction Efficiency Based on the Coupling-Slot Configuration in an Extended Interaction Oscillator

    摘要: A method aimed at improving the beam-wave interaction efficiency by changing the coupling slot configuration has been proposed in the study of extended interaction oscillators (EIOs). The dispersion characteristics, coupling coefficient and interaction impedance of the high-frequency structure based on different types of coupling slots have been investigated. Four types of coupled cavity structures with different layouts of the coupling slots have been compared to improve the beam-wave interaction efficiency, so as to analyze the beam-wave interaction and practical applications. In order to determine the improvement of the coupling slot to a coupled cavity circuit in an EIO, we designed four nine-gap EIOs based on the coupled cavity structure with different coupling slot configurations. With different operating frequencies and voltages takes into consideration, beam voltages from 27 to 33 kV have been simulated to achieve the best beam-wave interaction efficiency so that the EIOs are able to work in the 2π mode. The influence of the Rb and the ds on the output power is also taken into consideration. The Rb is the radius of the electron beam, and the ds is the width of the coupling slot. The simulation results indicate that a single-slot-type EIO has the best beam-wave interaction efficiency. Its maximum output power is 2.8 kW and the efficiency is 18% when the operating voltage is 31 kV and electric current is 0.5 A. The output powers of these four EIOs that were designed for comparison are not less than 1.7 kW. The improved coupling-slot configurations enables the extended interaction oscillator to meet the different engineering requirements better.

    关键词: Output power,Coupling slot configuration,Extended interaction oscillator,Beam-wave interaction efficiency

    更新于2025-09-23 15:22:29

  • [IEEE 2018 9th International Conference on Ultrawideband and Ultrashort Impulse Signals (UWBUSIS) - Odessa, Ukraine (2018.9.4-2018.9.7)] 2018 9th International Conference on Ultrawideband and Ultrashort Impulse Signals (UWBUSIS) - Mathematical Model of Transverse Circumferential Slots in Coaxial Line Shield With Nonhomogeneous Dielectric Interior

    摘要: Excitation and scattering problem for transverse circumferential slots in a shield of coaxial line with dielectric insert just under the slot has been solved. Internal conductivity is determined including multiple reflections that are caused by dielectric insert of a finite length filling the feeder cross-section up. Formulas for radiation and reflection coefficients are presented.

    关键词: dielectric insert,circumferential slot,reflection coefficient,radiation coefficient,line,conductivity,magnetomotive,force,coaxial

    更新于2025-09-23 15:21:21

  • [IEEE 2019 IEEE International Conference on Microwaves, Antennas, Communications and Electronic Systems (COMCAS) - Tel-Aviv, Israel (2019.11.4-2019.11.6)] 2019 IEEE International Conference on Microwaves, Antennas, Communications and Electronic Systems (COMCAS) - Overview of High Frequency Electronics Integration Concepts for Gap waveguide based High Gain Slot Antenna Array

    摘要: This paper presents an overview of different low-loss microstrip to waveguide transition designs suitable for integrating millimeter wave electronics to a gap waveguide based slot array. Typically, E-plane probe type of transitions are widely used at mmWave frequency range to couple RF signal from a TX/RX MMIC to the waveguide section. H-plane split-blocks are avoided due to leakage problem from tiny slits formed by imperfect metal connections. On the other hand, the traditional slot arrays are built using H-plane split blocks. This makes it very challenging to integrate electronics and other passive components such as diplexer filter directly to a high gain planar antenna array. To overcome this above mentioned problem, we propose to use low-loss H-plane transitions to integrate RF electronics with the multi-layer gap waveguide based slot array. We demonstrate a completely packaged front-end at E-band, showing the potential of the gap waveguide technology to build a very compact full-duplex wireless system.

    关键词: E-plane transition,Slot arrays,Full-duplex,Integration and packaging,Gap waveguide

    更新于2025-09-23 15:21:01

  • As2Se3-Ge11.5As24Se64.5 based mid-infrared dual nano-slot optical waveguide with huge and wavelength tunable dispersion

    摘要: An As2Se3-Ge11.5As24Se64.5 based dual nano-slot waveguide with huge chromatic dispersion at mid-infrared is proposed. The large chromatic dispersion at the target wavelength is achieved induced by resonance interaction. The characteristics of dispersion are investigated by employing the FDTD method. The simulation results indicate that by optimizing the geometrical parameters, the maximum dispersion of -3.48×105 ps·nm-1·km-1 over a full width at FWHM of 2 nm at 3000 nm has been attained. A flat and ultra-large dispersion of -3.48×105 ps·nm-1·km-1 from 2980 to 3010 nm is achieved by cascading the dual-slot waveguides. The relative dispersion magnitude fluctuation is less than 1.85%.

    关键词: chalcogenide waveguide,chromatic dispersion,dual-slot waveguide,mid-infrared

    更新于2025-09-23 15:21:01

  • Performance analysis of slot waveguide using aluminum nitride in slot region

    摘要: The major obstacle to accomplish an efficient photonic slot waveguide is its comparatively high propagation loss. In the current work, the silicon-on-insulator based slot waveguide with ultra-low propagation loss has been presented using aluminum nitride (AlN) in the slot region. The performance analysis of the slot waveguide has been done by varying the slot gaps from 20 to 240 nm and by varying the arm width from 160 to 340 nm. As compared with the recently reported works based on different slot waveguides, relatively smaller propagation loss of ~ 0.7 dB/cm has been predicted using the AlN based slot waveguide having a slot gap of 120 nm and arm width of 240 nm. Simulation results have demonstrated that the presence of AlN in the slot gap/low-index region, sandwiched between two high-index (silicon) regions, causes the discontinuity of the electric field of quasi-TE mode between the high-index regions. This results in high confinement of light with the smaller propagation loss in the slot region. Along with this, it has also been observed that the presented slot waveguide has the appreciably good propagation length, with low dispersion characteristics. Hence, this kind of analysis can be extended to realize the various optical devices/applications, such as for coupling, sensing, switching, etc.

    关键词: Propagation loss,Aluminum nitride,Slot waveguide,Effective refractive index (ERI),Dispersion

    更新于2025-09-23 15:21:01

  • Late-stage Customization in Volume Production of Organic Photovoltaics

    摘要: Organic photovoltaics (OPV) in free-form shapes have become a unique feature compared to other thin-film photovoltaic technologies. The ability to conform coated layers to any form of shape or structure is a game changer for OPV and creates a paradigm shift in conventional energy businesses. As urban growth prevails, the energy requirement must be compensated by modern means and OPVs provide unique properties where its form or shape can be fully customized. This creates a synergy as they are then easily integrated onto structures or even products. By doing so not only the space requirements are diminished but the energy is delivered directly to the point of use rather than having them transported from central harvesting. The present communication discusses the advances in realizing such free-from patterns by structuring the functional layers to shape after they have been deposited which is referred to as late-stage customization. Using this approach, a pre-coated generic OPV material can be converted into any design upon customer request. The advantages include easier planning, shorter lead times in production as well as paving the way towards lean manufacturing.

    关键词: renewable energies,mass production,organic photovoltaics (OPV),laser scribing,slot-die coating,module customization,roll-to-roll fabrication,dielectric material

    更新于2025-09-23 15:21:01

  • Polarization-independent hybrid plasmonic coupler based on T-shaped slot waveguide

    摘要: In this paper, a novel polarization-independent hybrid plasmonic coupler based on a T-shaped slot waveguide is proposed and investigated by numerical simulations using the finite element method. The structure supports both the TE-polarized slot waveguide mode and the TM-polarized plasmonic mode, offering a greater possibility to achieve the polarization-independent operation. The simulation results show that with proper structural parameters, the waveguide coupler with high extinction ratios of 31.2 dB (TE) and 30 dB (TM) and low insertion losses of 0.38 dB (TE) and 2.04 dB (TM) can be achieved at a telecommunication wavelength of 1550 nm. An investigation of the influence of structural perturbations indicates that the proposed coupler also has a good tolerance to fabrication errors. The proposed structure has potential applications in the field of subwavelength integrated photonic circuits.

    关键词: polarization-independent,hybrid plasmonic coupler,finite element method,T-shaped slot waveguide,photonic integrated circuits

    更新于2025-09-23 15:21:01

  • Design and Simulation of a Slot Waveguide Array Antenna (SWAA) for Satellite Communications

    摘要: One of the most used antennas today, is that of slots in waveguides. These antennas are an important type within the microwave range with various applications in electronic communications systems, radar, and satellite applications, due to its high power capacity, high efficiency, low weight, compact structure and few lateral lobes, all added together to its proven resistance to radiation, high temperatures and vibration, characteristics without which they can not be used in aerospace applications. The following lines show the design and simulation of a Slot Waveguide Array Antenna (SWAA) for satellite communications in the 30 GHz band. The antenna will be approximately 170x170 mm, constituted by 24x24 slots. It will be fed by waveguides in a lower layer connected to the radiating guides through slots. The modeling and design of the different elements that make up the power grid as T- junctions and elbows in the E and H planes were carried out.

    关键词: 30 GHz band,SWAA,waveguide slots,Slot Waveguide Array Antenna,satellite communications

    更新于2025-09-23 15:21:01

  • A Wideband Dual-Slot Coupled Multiple Dense Dielectric Patch Antenna

    摘要: A dual-slot coupled multiple dense dielectric (DD) patch antenna is proposed to achieve wide bandwidth. The multiple DD patches operating at quasi-TM11 mode and quasi-TM21 mode, which is excited by the dual-slot. In addition, the dual-slot also functions as an effective radiator as with DD patches. Thus, five modes including two modes of DD patches and three modes of the dual slots can be obtained to support wide bandwidth. Compared with the reported DD patch antennas, the proposed design exhibits wide bandwidth and relatively high gain with a finite ground size. For demonstration, one prototype operating at 8.98 GHz is fabricated with the ground size of 0.63 λ0 ×0.78 λ0 (λ0 is the wavelength in the free space at the center frequency), the 10-dB impedance matching bandwidth of 81.9% and the peak gain of 9.27 dBi.

    关键词: multiple dense dielectric patch,Dual-slot coupled,wide bandwidth

    更新于2025-09-23 15:21:01