Metallic nanostructures play an essential role in electromagnetic manipulations due to the localization and enhancement of electromagnetic waves in nanogaps. Scaling down the dimensions of the gap, such as the gap width and the thickness, is an effective way to enhance light-matter interaction with colossal field enhancement. However, reducing the thickness below 10 nanometers still suffers from fabrication difficulty and unintended direct transmission through metals. Here, we fabricate effective-zero-thickness slot antennas by stepping metals in the vicinity of the gaps to confine electromagnetic waves in tiny volumes. We analyze and simulate terahertz transmission, and demonstrate the absorption enhancement of molecules in the slot antennas. Our fabrication technique provides a simple but versatile tool for maximum field enhancement and molecular sensing.
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http://dx.doi.org/10.1364/OE.427061 | DOI Listing |
Sci Rep
January 2025
Faculty of Electric and Computer, Malek Ashtar University of Technology, Tehran, Iran.
In this paper, a multilayer monopulse antenna at Ku-Band with high efficiency, high power handling capability, high gain, 45° linear polarization and low sidelobe is presented. A new slot antenna is proposed as a radiating element based on a cavity-backed slot-coupled patch antenna. Using an enclosed cavity structure reduces coupling between antenna elements, thus increasing the antenna efficiency.
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December 2024
Centre-Energie Materiaux et Telecommunications, Institut National de la Recherche Scientifique, Montreal, QC H5A 1K6, Canada.
This paper presents a high-performance circularly polarized (CP) magneto-electric (ME) dipole antenna optimized for wideband millimeter-wave (mm-wave) frequencies, specifically targeting advancements in 5G and 6G technologies. The CP antenna is excited through a transverse slot in a printed ridge gap waveguide (PRGW), which operates in a quasi-transverse electromagnetic (Q-TEM) mode. Fabricated on Rogers RT 3003 substrate, selected for its low-loss and cost-effective properties at high frequencies, the design significantly enhances both impedance and axial ratio (AR) bandwidths.
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December 2024
State Key Laboratory of Millimeter-Waves, School of Information Science and Engineering, Southeast University, Nanjing 210096, China.
This paper presents a D-band dual linear-polarized wideband high-gain reflectarray (RA) antenna using low-temperature co-fired-ceramic (LTCC) technology. The proposed element comprises a dual-polarized magnetoelectric (ME) dipole and a multilayer slot-coupling substrate-integrated waveguide (SIW) phase-delay structure, which are organized in accordance with the receiving/reradiating (R/R) principle. The coverage of phase shifts for both orthogonal polarizations is set to be greater than 360 degrees by varying the length of the phase-delay structure.
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December 2024
Department of Electrical Engineering, Chalmers University of Technology, Gothenburg, Sweden.
This study presents the design of a high-gain 16 × 16-slot antenna array with a low sidelobe level (SLL) using a tapered ridge gap waveguide feeding network for Ka-band applications. The proposed antenna element includes four cavity-backed slot antennas. A tapered feeding network is designed and utilized for unequal feeding of the radiating elements.
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December 2024
Computer Engineering Department, Lorestan University, Khorramabad, Iran.
This paper presents a slot antenna integrated with a split ring resonator (SRR) and feed line, designed to achieve a high Q-factor while maximizing channel capacity utilization. By incorporating a lens into the dielectric resonator antenna (DRA), we enhance both bandwidth and directivity, with the dielectric material's permittivity serving as a key control parameter for radiation characteristics. We explore water and ethanol as controllable dielectrics within the terahertz (THz) frequency range (0.
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