scholarly journals Wideband Dual-Polarized VHF Antenna for Space Observation Applications

Sensors ◽  
2020 ◽  
Vol 20 (15) ◽  
pp. 4351
Author(s):  
Alexandru Tatomirescu ◽  
Alina Badescu

This work presents the design for an antenna element that can be used in radio arrays for the monitoring and detecting of radio emissions from cosmic particles’ interactions in the atmosphere. For these applications, the pattern stability over frequency is the primary design goal. The proposed antenna has a high gain over a relative bandwidth of 88%, a beamwidth of 2.13 steradians, a small group delay variation and a very stable radiation pattern across the frequency bandwidth of 110 to 190 MHz. It is dual polarized and has a simple mechanical structure which is easy and inexpensive to manufacture. The measurements show that the ground has insignificant impact on the overall radiation pattern.

2021 ◽  
Vol 2021 ◽  
pp. 1-8
Author(s):  
Yuxuan Huang ◽  
Zeqi Zhu ◽  
Shuting Cai ◽  
Xiaoming Xiong ◽  
Yuan Liu

A wideband dual-polarized multidipole antenna for base station applications is proposed. It consists of a pair of large square-shaped loop dipoles and a pair of small rectangle loop dipoles as radiation elements. A pair of small rectangle loop dipoles is fed by T-shaped feed structure which is in the large square-shaped loop dipoles radiating arm so that the antenna generates an additional resonance and obtains a wider bandwidth. The proposed antenna was fabricated and measured, and the results show that the antenna achieves a wide impedance bandwidth of 63.7 % with VSWR<1.5 covering the frequency range from 1.55 to 3 GHz. A high isolation is better than 29 dB within the operating frequency bandwidth. Moreover, an average gain 8 dBi and a stable radiation pattern with 3 dB beamwidth of 69° ± 4° at H-plane are obtained.


Author(s):  
Le Minh Thuy

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.


Sensors ◽  
2020 ◽  
Vol 20 (18) ◽  
pp. 5233 ◽  
Author(s):  
Young-Jun Kim ◽  
Gunhark Noh ◽  
Han Lim Lee ◽  
Sungwook Yu

This article presents a dual-polarized, high gain multi-beam and high T/Rx channel-to-channel isolation antenna module for 24 GHz sensor applications. The proposed antenna is configured to support 2-Tx and 2-Rx channels with a pair of vertically polarized (VP) radiation pattern and a pair of horizontally polarized (HP) radiation pattern. Further, each linearly polarized T/Rx antenna is configured by 2 × 4 array with a multi-layer integrated feed network, resulting in four sets of 2 × 4 array antennas fabricated within a single printed circuit board (PCB). Since multiple RF channels must be ensured with minimal interference, high antenna-to-antenna, including Tx-to-Tx, Rx-to-Rx, and Tx-to-Rx port isolations in the proposed antenna are achieved by multi-layered feed network and four sets of T-shaped magnetic walls. To verify the performance of the proposed structure, a 2-Tx and 2-Rx antenna module was fabricated at 24 GHz. The fabricated antenna showed a measured maximum 10-dB impedance bandwidth of 3.9% with a maximum measured gain of 11.7 dBi, considering both Tx and Rx. Further, the measured channel-to-channel isolations were always better than 35.6 dB at 24 GHz.


Electronics ◽  
2020 ◽  
Vol 9 (9) ◽  
pp. 1376
Author(s):  
Ronis Maximidis ◽  
Diego Caratelli ◽  
Giovanni Toso ◽  
A. Bart Smolders

This paper proposes a novel high-gain antenna element that can be used in antenna arrays that only require a limited scan range. Each high-gain antenna element uses a linear sub-array of highly-coupled open-ended waveguides. The active central element of this sub-array is directly fed, while the remaining passive waveguides are reactively loaded. The loads are implemented by short-circuits positioned at various distances from the radiating aperture. The short-circuit positions control the radiation pattern properties and the scattering parameters of the array. The proposed sub-array antenna element is optimized in the presence of the adjacent elements and provides a high gain and a flat-top main lobe. The horizontal distance between the sub-array centers is large in terms of wavelengths, which leads to limited scanning capabilities in the E-plane. However, along the vertical axis, the element spacing is around 0.6 wavelength at the central frequency that is beneficial to achieve a wider scan range in the H-plane. We show that the sub-array radiation pattern sufficiently filters the grating lobes which appear in the array factor along the E-plane. To demonstrate the performance of the proposed array configuration, an array operating at 28.0 GHz is designed. The designed array supports scan angles up to ±7.5° along the E-plane and ±24.2° along the H-plane


1997 ◽  
Vol 14 (1) ◽  
pp. 68-74
Author(s):  
Yao Demiao ◽  
Cai Jianming ◽  
Jiang Mingzhi

2018 ◽  
Vol 2018 ◽  
pp. 1-9
Author(s):  
Hongyu Shi ◽  
Jianxing Li ◽  
Shitao Zhu ◽  
Anxue Zhang ◽  
Zhuo Xu

In this paper, we proposed a radiation pattern reconfigurable waveguide slot array antenna using liquid crystal (LC). Together with the waveguide slot, the designed complementary electric-field-coupled resonator functions like a switch controlled by the dielectric constant of the LC, which can control the antenna element to radiate or not. Thus, the array factor and radiation pattern can be manipulated. The proposed antenna was simulated, fabricated, and measured. Its radiation direction can be reconfigured to 46° or 0° at about 15 GHz.


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