scholarly journals Dielectric Slabs-Based Lens for Millimeter-Wave Beamforming

2022 ◽  
Vol 12 (2) ◽  
pp. 638
Author(s):  
Ali H. Alqahtani ◽  
Yosef T. Aladadi ◽  
Mohammed T. Alresheedi
Keyword(s):  
Refractive Index ◽  
Millimeter Wave ◽  
Effective Refractive Index ◽  
Horn Antenna ◽  
Slab Thickness ◽  
Antenna Element ◽  
Sidelobe Level ◽  
Spherical Lens ◽  
Single Antenna ◽  
Dielectric Lens

This paper proposes a dielectric slabs-based lens for millimeter-wave beamforming systems. The proposed lens is based on the graded steps of the effective refractive index of the semi-spherical lens. It consists of multiple dielectric slabs that match the selected gradient effective refractive index. These slabs have the same thicknesses and different radii. The slab thickness in this lens should not exceed a quarter of the operating wavelength to keep on a similar effective refractive index of the original semi-spherical lens. A horn antenna is used to examine the performance of the designed lens at 28 GHz frequency in terms of the maximum gain, sidelobe level, and 3 dB beamwidth. Sixteen switchable horn antennas are used to demonstrate lens capability for millimeter-wave beamforming. Every single antenna element is selected individually, thus the dielectric lens steers and enhances the corresponding radiation of the selected element in the desired direction.

scholarly journals Triangular Slot-Loaded Wideband Planar Rectangular Antenna Array for Millimeter-Wave 5G Applications

Electronics ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 778
Author(s):  
Iftikhar Ahmad ◽  
Houjun Sun ◽  
Umair Rafique ◽  
Zhang Yi
Keyword(s):  
Antenna Array ◽  
Millimeter Wave ◽  
Communication Systems ◽  
Ground Plane ◽  
Simulated Data ◽  
Impedance Bandwidth ◽  
Antenna Element ◽  
Single Antenna ◽  
Rectangular Patch ◽  
Half Power

This paper presents a design of a triangular slot-loaded planar rectangular antenna array for wideband millimeter-wave (mm-wave) 5G communication systems. The proposed array realizes an overall size of 35.5 × 14.85 mm2. To excite the array elements, a four-way broadband corporate feeding network was designed and analyzed. The proposed array offered a measured impedance bandwidth in two different frequency ranges, i.e., from 23 to 24.6 GHz and from 26 to 45 GHz. The single-antenna element of the array consists of a rectangular patch radiator with a triangular slot. The partial ground plane was used at the bottom side of the substrate to obtain a wide impedance bandwidth. The peak gain in the proposed array is ≈12 dBi with a radiation efficiency of >90%. Furthermore, the array gives a half-power beamwidth (HPBW) of as low as 12.5°. The proposed array has been fabricated and measured, and it has been observed that the measured results are in agreement with the simulated data.

SERIES FEED FAN-BEAM ANTENNA ARRAY WITH A LOW SIDELOBE LEVEL FOR POSITIONING SYSTEM

2020 ◽  
pp. 55-65
Author(s):  
Le Minh Thuy
Keyword(s):  
Antenna Array ◽  
Radiation Pattern ◽  
Amplitude Distribution ◽  
High Gain ◽  
Impedance Bandwidth ◽  
Antenna Element ◽  
Positioning System ◽  
Sidelobe Level ◽  
Single Antenna ◽  
Low Sidelobe

In this paper, a novel antenna array at 5GHz is presented with a low sidelobe level and wide impedance bandwidth for indoor positioning applications . The antenna array has the size of 450 ×57×0.8 mm3 with the high gain of 14.5dBi and the low SLL of -18 dB at 5GHz. The series feed using Unequal Split T-Junction is proposed with the Chebyshev-amplitude distribution to improve SLL. Besides the 1800 phase and amplitude distribution, by deploying driven elements above each single antenna element, the radiation pattern and the gain of the antenna aray are significantly improved.

scholarly journals H-plane horn antenna with enhanced directivity using conformal transformation optics

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Hossein Eskandari ◽  
Juan Luis Albadalejo-Lijarcio ◽  
Oskar Zetterstrom ◽  
Tomáš Tyc ◽  
Oscar Quevedo-Teruel
Keyword(s):  
Conformal Transformation ◽  
Phase Error ◽  
Three Dimensional ◽  
Physical Space ◽  
Horn Antenna ◽  
High Gain ◽  
Transformation Optics ◽  
Graded Index ◽  
Low Profile ◽  
Dielectric Lens

AbstractConformal transformation optics is employed to enhance an H-plane horn’s directivity by designing a graded-index all-dielectric lens. The transformation is applied so that the phase error at the aperture is gradually eliminated inside the lens, leading to a low-profile high-gain lens antenna. The physical space shape is modified such that singular index values are avoided, and the optical path inside the lens is rescaled to eliminate superluminal regions. A prototype of the lens is fabricated using three-dimensional printing. The measurement results show that the realized gain of an H-plane horn antenna can be improved by 1.5–2.4 dB compared to a reference H-plane horn.

scholarly journals NONLINEAR OPTICAL WAVEGUIDE STRUCTURE FOR SENSOR APPLICATION: TM CASE

2007 ◽  
Vol 21 (30) ◽  
pp. 5075-5089 ◽  
Author(s):  
HALA M. KHALIL ◽  
MOHAMMED M. SHABAT ◽  
SOFYAN A. TAYA ◽  
MAZEN M. ABADLA
Keyword(s):  
Refractive Index ◽  
Theoretical Analysis ◽  
Closed Form ◽  
Optical Waveguide ◽  
Effective Refractive Index ◽  
Nonlinear Optical ◽  
Waveguide Structure ◽  
Analytical Expressions ◽  
Evanescent Waveguide ◽  
Waveguide Sensor

In this work, we present an extensive theoretical analysis of nonlinear optical waveguide sensor. The waveguide under consideration consists of a thin dielectrica film surrounded by a self-focused nonlinear cladding and a linear substrate. The nonlinearity of the cladding is considered to be of Kerr-type. Both cases, when the effective refractive index is greater and when it is smaller than the index of the guiding layer, are discussed. The sensitivity of the effective refractive index to any change in the cladding index in evanescent optical waveguide sensor is derived for TM modes. Closed form analytical expressions and normalized charts are given to provide the conditions required for the sensor to exhibit its maximum sensitivity. The results are compared with those of the well-known linear evanescent waveguide sensors.

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