| 1. |
- Zhang, Yiming, et al.
(author)
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A Broadband High-Gain Circularly Polarized Wide Beam Scanning Leaky-Wave Antenna
- 2020
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In: IEEE Access. - : Institute of Electrical and Electronics Engineers (IEEE). - 2169-3536. ; 8, s. 171091-171099
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Journal article (peer-reviewed)abstract
- A new type of broadband circularly polarized leaky-wave antenna (LWA) with high-gain based on a corrugated substrate integrated waveguide (CSIW) structure is proposed and investigated. The CSIW structure that employs open-circuit stubs to replace metallic vias has the advantages of low-cost and easy fabrication as compared to conventional substrate integrated waveguides. Each unit-cell of the proposed LWA consists of two quarter-wavelength microstrip lines and a half-mode CSIW cell with three open-circuit stubs. Two M-shaped slots etched on the half-mode CSIW cell enables the generation of circularly polarized (CP) radiation. The full LWA, which consists of thirteen matched unit-cells cascaded along the direction of propagation enables continuous backward to forward beam scanning. The properties of the CSIW structure, including impedance matching and phase constant, are analyzed by Bloch impedance and dispersion simulations and the influence of the dimensions of the open-circuit stubs on the CP LWA performance is also investigated. A protype of the proposed LWA is fabricated and characterized. The measured results indicate that the proposed CSIW LWA has a high peak gain (9.3-12.5 dBi) throughout a large beam-scanning angle range from -28 degrees to +25 degrees, and the impedance bandwidth and 3-dB axial ratio (AR) bandwidth are over 40% covering the full Ka-band.
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| 2. |
- Chen, Hongzhi, et al.
(author)
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Terahertz polarization splitter based on a dual-elliptical-core polymer fiber
- 2016
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In: Applied Optics. - : OPTICAL SOC AMER. - 1559-128X .- 2155-3165. ; 55:23, s. 6236-6242
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Journal article (peer-reviewed)abstract
- A terahertz polarization splitter based on a dual-elliptical-core polymer fiber is proposed and theoretically optimized. Dual-elliptical cores with subwavelength-scale diameters are independently suspended within a fiber, which not only support two orthogonal polarization modes, being single-mode guided with low absorption losses, but also allow them to switch from one core to the other, with different coupling lengths. As a consequence, the two polarizations can be easily separated by choosing a suitable transmission length at a desired operation frequency. The transmission modes, coupling lengths for x- and y-polarizations, as well as the performance of the proposed polarization splitter at a center-frequency of 0.6 THz are investigated and numerically analyzed. A 1.43 cm long splitter with an ultralow loss of 0.4 dB, a high extinction ratio better than -10 dB and a bandwidth of 0.02 THz is achieved.
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| 3. |
- Lin, Yuxin, et al.
(author)
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A Simple High-Gain Millimeter-Wave Leaky-Wave Slot Antenna Based on a Bent Corrugated SIW
- 2020
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In: IEEE Access. - : IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC. - 2169-3536. ; 8, s. 91999-92006
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Journal article (peer-reviewed)abstract
- We propose a bent corrugated substrate integrated waveguide (BCSIW) structure that can be used to design a high gain leaky wave antenna (LWA). The design removes the need for a metallic via fabrication process needed for standard substrate integrated waveguides (SIW) and displays superior performance to previously reported structures. We use simulations to compare the performance of the proposed BCSIW LWA to equivalent standard SIW and corrugated SIW (CSIW) structures, as well as experimentally characterize a fabricated BCSIW LWA. Simulation results show that the BCSIW structure can help improve the impedance bandwidth of a slotted LWA by about 14.7 while still maintaining high gain (about 13.217.4 dBi) as compared to an LWA based on a CSIW structure. Measurement results indicate that the proposed BCSIW LWA has a wide impedance bandwidth (32.6) and a high peak gain (1216.2 dBi) throughout a large frequency range from 22 to 29.2 GHz with a large beam angle range from 69 to 10.
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| 4. |
- Huang, Qiangsheng, et al.
(author)
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LiNbO3 waveguide with embedded Ag nanowire and 3L MoS2 for strong light confinement and ultra-long propagation length in the visible spectral range
- 2021
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In: Optics Express. - : The Optical Society. - 1094-4087. ; 29:5, s. 7168-7178
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Journal article (peer-reviewed)abstract
- A vertical slot LiNbO3 waveguide with an Ag nanowire and 3L MoS2 embedded in the low-refractive index slot region is proposed for the purpose of improving light confinement. We find that the proposed waveguide has a novel dielectric based plasmonic mode, where local light field is enhanced by the Ag nanowire. The mode exhibits an extremely large figure of merit (FoM) of 6.5x10(6), one order of magnitude larger than that the largest FoM of any plasmonic waveguide reported in the literature to date. The waveguide also has an extremely long propagation length of 84 cm in the visible wavelength at 680 nm. Furthermore, the waveguide has a low sub-micro bending loss and can be directly connected to all-dielectric waveguides with an extremely low coupling loss. The proposed vertical slot LiNbO3 waveguide is a promising candidate for the realization of ultrahigh integration density tunable circuits in the visible spectral range.
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| 5. |
- Luo, Peng, et al.
(author)
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Leaky-Wave Antenna With Wide Scanning Range Based on Double-Layer Substrate Integrated Waveguide
- 2020
-
In: IEEE Access. - : IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC. - 2169-3536. ; 8, s. 199899-199908
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Journal article (peer-reviewed)abstract
- A leaky-wave antenna (LWA) based on the double-layer substrate integrated waveguide (SIW) that has a wide scanning range within a narrow bandwidth is proposed. The LWA consists of two layers, each of which consists of multiple elemental SIWs arranged in parallel at each layer while the direction of the SIWs in the two layers are at an oblique angle to each other. The elemental top layer SIWs are connected to those in the bottom layer though parallelogram-shaped slots, so that the two layers together form a double-layer SIW. Thin slots etched on the upper surface of each elemental SIW of the top layer act as radiating structures. As the phase difference between the radiating slots of adjacent elemental SIWs can be enlarged by the waveguide length, wide-angle beam scanning is achieved within a specific frequency bandwidth. The proposed LWA has a scanning range from -58 degrees to 49 degrees in a relative bandwidth of 6.45%, from 12.75 GHz to 13.6 GHz. The scanning rate (SR), defined as the scanning range divided by the relative bandwidth, is up to 16.5. The size of structure is compact, which is 4.0 lambda(0) x 3.6 lambda(0) x 0.04 lambda(0). The proposed LWA is suitable for radar or communication system applications.
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