Slot antenna for mobile base station using AMC

2014 ◽  
Vol 6 (5) ◽  
pp. 527-535 ◽  
Author(s):  
Mohamed S. El-Gendy ◽  
Haythem H. Abdullah ◽  
Esmat A. Abdallah

In this paper, a new configuration of dual-band, dual-polarized microstrip antenna applicable to mobile base stations is proposed. The concept behind the new design is the use of an artificial magnetic conductor (AMC) structure that operates in the required two bands beneath a radiating diamond shaped slot. The choice of the diamond-shaped slot is due to its support of an infinite number of resonant modes where the dimensions of the diamond shape have more degree of freedom that controls the excited modes when compared to the rectangular slot. The proposed antenna works over the 870–960 MHz (GSM850/GSM900) band and the 1710–2170 MHz (DCS1800/PCS1900/UMTS2100) bands for mobile communication systems. The antenna is suitable for transmitting and receiving mobile signals since it has two ports of orthogonal polarization. The antenna is fabricated on a combination of FR4 dielectric substrate and foam layers in order to achieve low cost. The proposed antenna yields high isolation between its two ports not exceeding −30 dB and a front-to-back ratio exceeding 15 dB. The average antenna gains are about 6.6 dBi at the GSM850/GSM900, 7.1 dBi at the DCS1800/PCS1900, and 6.8 dBi at the UMTS2100 bands. The theory of radiation is proved analytically and verified by comparing its results with some simulated results. Finally, a good agreement between the simulated and measured results is noticed.

Sensors ◽  
2021 ◽  
Vol 21 (11) ◽  
pp. 3584
Author(s):  
Milembolo Miantezila Junior ◽  
Bin Guo ◽  
Chenjie Zhang ◽  
Xuemei Bai

Cellular network operators are predicting an increase in space of more than 200 percent to carry the move and tremendous increase of total users in data traffic. The growing of investments in infrastructure such as a large number of small cells, particularly the technologies such as LTE-Advanced and 6G Technology, can assist in mitigating this challenge moderately. In this paper, we suggest a projection study in spectrum sharing of radar multi-input and multi-output, and mobile LTE multi-input multi-output communication systems near m base stations (BS). The radar multi-input multi-output and mobile LTE communication systems split different interference channels. The new approach based on radar projection signal detection has been proposed for free interference disturbance channel with radar multi-input multi-output and mobile LTE multi-input multi-output by using a new proposed interference cancellation algorithm. We chose the channel of interference with the best free channel, and the detected signal of radar was projected to null space. The goal is to remove all interferences from the radar multi-input multi-output and to cancel any disturbance sources from a chosen mobile Communication Base Station. The experimental results showed that the new approach performs very well and can optimize Spectrum Access.


Sensors ◽  
2021 ◽  
Vol 21 (4) ◽  
pp. 1439
Author(s):  
Janghyuk Youn ◽  
Woong Son ◽  
Bang Chul Jung

Recently, reconfigurable intelligent surfaces (RISs) have received much interest from both academia and industry due to their flexibility and cost-effectiveness in adjusting the phase and amplitude of wireless signals with low-cost passive reflecting elements. In particular, many RIS-aided techniques have been proposed to improve both data rate and energy efficiency for 6G wireless communication systems. In this paper, we propose a novel RIS-based channel randomization (RCR) technique for improving physical-layer security (PLS) for a time-division duplex (TDD) downlink cellular wire-tap network which consists of a single base station (BS) with multiple antennas, multiple legitimate pieces of user equipment (UE), multiple eavesdroppers (EVEs), and multiple RISs. We assume that only a line-of-sight (LOS) channel exists among the BS, the RISs, and the UE due to propagation characteristics of tera-hertz (THz) spectrum bands that may be used in 6G wireless communication systems. In the proposed technique, each RIS first pseudo-randomly generates multiple reflection matrices and utilizes them for both pilot signal duration (PSD) in uplink and data transmission duration (DTD) in downlink. Then, the BS estimates wireless channels of UE with reflection matrices of all RISs and selects the UE that has the best secrecy rate for each reflection matrix generated. It is shown herein that the proposed technique outperforms the conventional techniques in terms of achievable secrecy rates.


2021 ◽  
Author(s):  
Muhammad Salman Bashir ◽  
Mohamed-Slim Alouini

<div>Due to their flexibility and low cost deployment, unmanned aerial vehicles (UAV) will most likely act as base stations and backhaul relays in the next generation of wireless communication systems. However, these UAVs---in the untethered mode---can only operate for a finite time due to limited energy they carry in their batteries. In free-space optical communications, one solution is to transport both the data and the energy from the source to the UAV through the laser beam---a concept known as <i>simultaneous lightwave information and power transfer</i> (SLIPT). In this study, we have analyzed the SLIPT scheme for laser-powered decode-and-forward UAV relays in an optical wireless backhaul. The major goal of this study is to optimally allocate the received beam energy between the decoding circuit, the transmitting circuit and the rotor block of the relay in order to maximize a quality-of-service metric such as maximum achievable rate, outage or error probabilities. As expected, we note that the optimal power allocation depends heavily on the source-relay and relay-destination channel conditions. In the final part of this study, we have maximized the operational time of the UAV relay given that the maximum achievable rate stays above a certain threshold in order to meet a minimum quality-of-service requirement.</div>


Author(s):  
Walder de Jesús Canova García

Resumen El creciente número de estaciones base de telefonía móvil celular alrededor de sectores residenciales o tránsito de personas, causa preocupación en la comunidad sobre si la radiación de campos electromagnéticos puedan causar riesgos en la salud. Internacionalmente existen estándares que establecen límites a las diversas fuentes de campos electromagnéticos para garantizar que se minimizan los riesgos en la salud. Cada país adopta dentro de su legislación algún estándar o recomendación y exige su cumplimiento a los operadores de estaciones de telecomunicaciones, por ejemplo en Colombia rige el decreto 195 de 2005. El artículo presenta una evaluación, basados en mediciones técnicas en el 2010, para obtener los niveles de exposición a campos electromagnéticos generados por las antenas instaladas en las estaciones base de telefonía móvil. Luego aparece el procedimiento general de mediciones, donde incluye el plan ejecutorial de mediciones, la configuración de la instrumentación y la caracterización de los lugares y puntos de medición. Por último, los resultados medidos en algunos lugares, donde las antenas de transmisión cumplían con la normativa adoptada en Colombia. Palabras Clave: Exposición a campos Electromagnéticos, Estaciones base de Telefonía móvil celular, Mediciones de banda angosta.   Abstract The growth of installations of transmitting antennas on base stations surrounding residential spaces or person traffic causes concerns in the community, about whether the radiation of electromagnetic fields of transmitting antennas in mobile base station can generate health risk. Over the world, there are standards that establish maximum levels permitted to different electromagnetic field sources to accomplish security ranges for health risks. Each country adopts in their legislation some international standard and requires to telecommunication operators stations for its compliance. In Colombian, the decree 195 of 2005 is still valid. This article shows an assessment, based on technical measurements developed in 2010, to acquire the electromagnetic field exposure levels generated by transmitting antennas installed on Mobile Base Station. This assessment includes the measurement system procedure: plan of measurement, instrumental configuration, and characterization of measurement places. Finally, here presents the measured results in some places, which exposure levels satisfied the adopted legislation in Colombia. Keywords: Electromagnetic Field Exposure, Mobile Base Stations, Narrowband Measurement.


2021 ◽  
Vol 35 (11) ◽  
pp. 1418-1419
Author(s):  
Yuhao Feng ◽  
Yiming Chen ◽  
Atef Elsherbeni ◽  
Khalid Alharbi

A compact size arrow shaped patch in a rectangular slot antenna is designed for 5G communications in the lower 3 to 6 GHz band. The antenna element is fed through a coplanar waveguide with partial ground plane for better impedance matching with 50 Ohms across the entire band. The maximum gain of a single element is 3.8 dB at 3.7 GHz, while for linear arrays of 5 and 15 elements with uniform excitation the maximum gains are 10.9 dB and 16 dB, respectively. The 5 and 15 elements arrays provide scanning range with no significant degradation of the main beam up to 30˚ and 45˚, respectively. The properties of this antenna element makes it suitable for 5G wireless mobile devices and miniaturized base stations antenna arrays.


Author(s):  
Mohamad Kamal A Rahim ◽  
Huda A. A. Majid ◽  
Mohamad Rijal Hamid

Reconfigurable antennas have attracted a lot of attention especially in future wireless communication systems. Superior features such as reconfigurable capability, low cost, multi-purpose functions and size miniaturization have given reconfigurable antennas advantage to be integrated into a wireless systems. In this chapter, two types of reconfigurable antennas are discussed. First, frequency reconfigurable narrowband microstrip slot antenna (FRSA) is presented. The proposed antenna is designed to operate at six reconfigurable frequency bands from 2 GHz to 5 GHz with bidirectional radiation pattern. The second antenna design is frequency reconfigurable narrowband patch-slot antenna (FRPSA) is presented. The antenna is a combination of a microstrip patch and slot antenna. Nine different narrow bands are produced by tuning the effective length of the slot. The performances of the antenna in term of simulated and measured results are presented. In conclusion, good agreement between the simulated and measured results has been attained.


Frequenz ◽  
2019 ◽  
Vol 73 (9-10) ◽  
pp. 339-351
Author(s):  
Rohit Kumar Saini

Abstract A novel dual-band rectangular slot antenna is presented for dual-sense reconfigurable polarization. A W-shaped microstrip feedline and two rectangular parasitic patches are used to obtain dual-band circular polarization. Further, the feedline is modified so that the senses of polarization at the two bands are opposite. By introducing PIN-diodes in the feed lines, polarization can be switched among left-hand circular polarization (LHCP), right-hand circular polarization (RHCP), and linear polarization (LP). A prototype dual-band dual-sense antenna with f01 = 1.9 GHz and f02 = 3.45 GHz is fabricated in a 1.6 mm thick FR4 substrate. The measured circular polarized bandwidths are more than 7.6 % for the lower band and 5 % for the upper band.


Author(s):  
Vincent Anayochukwu Ani ◽  
Nzeako Anthony Ndubueze

This paper explores the best energy options by which the choice of the most energy optimized solution for a given GSM Base Station Site and location in any rural area in Nigeria can be made. The patterns of load consumption by mobile base stations at various geographical locations in rural areas are studied and suitably modeled for optimization using HOMER software. Simulation results show the optimized energy options to be superior to conventional solutions whereby diesel generators are currently used to power GSM Base Station Sites around Nigeria. Total Net Present Cost (NPC) and total impact on the environment are used as indices for measuring the optimization level of each energy solution. The solution with the highest optimization value is considered to be the best energy option for that Base Station Site.


2003 ◽  
Vol 36 (5) ◽  
pp. 381-385 ◽  
Author(s):  
Cuthbert M. Allen ◽  
Atef Z. Elsherbeni ◽  
Charles E. Smith ◽  
Chun-Wen P. Huang ◽  
Kai-Fong Lee

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