scholarly journals On the Design of Dual-Polarised Linear Antenna Arrays with Enhanced Port-to-Port Isolation

Sensors ◽  
2020 ◽  
Vol 20 (21) ◽  
pp. 6105
Author(s):  
Dariusz Wójcik ◽  
Maciej Surma ◽  
Artur Noga ◽  
Mirosław Magnuski

The paper describes the process of designing a dual-polarised linear antenna array with enhanced port-to-port isolation, with the example of a four-element array with isolation better than 60 dB for the U-NII 5.15–5.925 GHz band. As a single antenna, dual-polarised electromagnetically coupled microstrip antennas were used with port-to-port isolation not exceeding 25 dB. A significant improvement in the isolation of the array was achieved thanks to the application of a dedicated feeding network. On the basis of theoretical analysis, a mathematical model describing port-to-port isolation was developed. Circuit and full-wave simulations were carried out to show the influence of electromagnetic couplings between antennas and/or the microstrip lines of the feeding network and the selection of phase shifters/power dividers on the isolation. The fabricated prototype is characterised by a gain of about 14 dBi, polarisation purity of at least −27 dB within the main lobe and close to expectations isolation better than 57 dB within the whole operational band.

2019 ◽  
Vol 30 ◽  
pp. 05030
Author(s):  
Viacheslav Rudakov ◽  
Victor Sledkov

A new design of the antenna array for mobile base stations providing two orthogonal polarizations in 1.71-2.17GHz frequency band is proposed. The antenna array includes 16 radiators, 12 power dividers and two phase shifters disposed on a metal reflector having dimensions 320×1387 mm. The developed antenna array contains less radiators and power dividers than other known antennas of this kind therefore one is cheaper for production. The fabricated sample of the proposed antenna array has return loss is better than -18.5dB and isolation better than 33dB. Beam width in the horizontal plane is equal 36 ± 4 degrees and side lobes level doesn’t exceeding -20dB. The antenna array provides gain=20.5dBi.


Author(s):  
Bhargav Appasani ◽  
Rahul Pelluri ◽  
Vijay Kumar Verma ◽  
Nisha Gupta

Genetic Algorithm (GA) is a widely used optimization technique with multitudinous applications. Improving the performance of the GA would further augment its functionality. This paper presents a Crossover Improved GA (CIGA) that emulates the motion of fireflies employed in the Firefly Algorithm (FA). By employing this mimicked crossover operation, the overall performance of the GA is greatly enhanced. The CIGA is tested on 14 benchmark functions conjointly with the other existing optimization techniques to establish its superiority. Finally, the CIGA is applied to the practical optimization problem of synthesizing non-uniform linear antenna arrays with low side lobe levels (SLL) and low beam width, both requirements being incompatible. However, the proposed CIGA applied for the synthesis of a 12 element array yields an SLL of [Formula: see text]29.2[Formula: see text]dB and a reduced beam width of 19.1[Formula: see text].


2020 ◽  
Vol 10 (5) ◽  
pp. 6259-6263
Author(s):  
D. T. T. My ◽  
H. N. B. Phuong ◽  
T. T. Huong ◽  
B. T. M. Tu

This paper proposes the design of a four-element array planar antenna based on a single antenna that combines the Double Positive (DPS) and Epsilon Negative (ENG) materials. The single antenna consists of a microstrip segment (which is equivalent to a DPS material) connected to a grounded microstrip segment (which is equivalent to an ENG material). T-Junction power dividers with one-input and two-output ports are used for feeding the two-element and the four-element array antennas. The proposed array antenna is designed to operate optimally at 30GHz frequency under Finite Element Method (FEM)-based simulation. The obtained simulation results show that the proposed array antennas have good radiation performances, in which the four-element array antenna has a -10dB bandwidth ranging from 28.7 to 33.4GHz and 12.9dBi gain.


Author(s):  
Mỹ Đặng Thị Từ

This paper proposes one-dimensional antenna arrays of the four-element and the eight-element using composite materials. Firstly, the single element is designed to resonate at Zeroth-order using a pair of Double positive (DPS) and Epsilon negative (ENG) materials meta-structured transmission line (MTL). Secondly, three of 1:2 T-Junction power dividers and seven of 1:2 T-Junction power dividers based on micro-strip technology are designed for feeding the four-element and the eight-element array antennas, respectively. Finally, the proposed arrays are optimized using FEM-based simulation to operate at the frequency of 8,5 GHz. The simulated results show that both antenna arrays have Zeroth-order resonance (ZOR) property, in which the four-element array has a bandwidth spreading from 8.39 to 8.61 GHz and a maximum gain of 8.82 dB while the other one of the eight-element array is 8.39 – 8.60 GHz and 12.2 dB, respectively. The proposed array antennas can be used for wireless applications or mobile communications.


2018 ◽  
Vol 8 (12) ◽  
pp. 2625 ◽  
Author(s):  
Sara Salem Hesari ◽  
Jens Bornemann

This paper describes a novel feed system for compact antipodal Vivaldi antenna arrays on a single layer of substrate integrated waveguide (SIW) by using SIW H-plane right-angled power dividers. The proposed antenna systems are composed of a Vivaldi array and an H-plane right-angled corner power divider which includes an over-moded waveguide section. Based on the number of antennas in the Vivaldi array, mode converter sections at K-band and Ka-band frequencies are designed, fabricated, and measured when feeding Vivaldi antenna arrays with two, three, and four antennas. Right-angled SIW power dividers are employed to obtain controllable phase distribution over the output ports which consequently controls the beam shapes of the systems. The phase relationships in the output ports are varied to obtain different pattern directions for different applications. The two-way divider system with 180-degree phase difference and three-way divider system are fabricated and measured; simulation results are presented for other designs. The measured results are in good agreement with simulations which confirms the design approach. All systems achieve good performance and meet all design goals including a return loss better than 10 dB in the operating bandwidth, gain higher than 8 dB for all systems, and radiation and polarization efficiencies higher than 80% and 98%, respectively.


2019 ◽  
Vol 9 (01) ◽  
pp. 47-54
Author(s):  
Rabbai San Arif ◽  
Yuli Fitrisia ◽  
Agus Urip Ari Wibowo

Voice over Internet Protocol (VoIP) is a telecommunications technology that is able to pass the communication service in Internet Protocol networks so as to allow communicating between users in an IP network. However VoIP technology still has weakness in the Quality of Service (QoS). VOPI weaknesses is affected by the selection of the physical servers used. In this research, VoIP is configured on Linux operating system with Asterisk as VoIP application server and integrated on a Raspberry Pi by using wired and wireless network as the transmission medium. Because of depletion of IPv4 capacity that can be used on the network, it needs to be applied to VoIP system using the IPv6 network protocol with supports devices. The test results by using a wired transmission medium that has obtained are the average delay is 117.851 ms, jitter is 5.796 ms, packet loss is 0.38%, throughput is 962.861 kbps, 8.33% of CPU usage and 59.33% of memory usage. The analysis shows that the wired transmission media is better than the wireless transmission media and wireless-wired.


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