scholarly journals Wideband and UWB Antennas for Wireless Applications: A Comprehensive Review

2017 ◽  
Vol 2017 ◽  
pp. 1-45 ◽  
Author(s):  
Renato Cicchetti ◽  
Emanuela Miozzi ◽  
Orlandino Testa
Keyword(s):  
Communication Systems ◽  
Base Stations ◽  
Portable Devices ◽  
Comprehensive Review ◽  
Dielectric Resonator Antennas ◽  
Analysis And Design ◽  
Wireless Applications ◽  
Uwb Antennas ◽  
Time Domain Response ◽  
Manufacturing Technologies

A comprehensive review concerning the geometry, the manufacturing technologies, the materials, and the numerical techniques, adopted for the analysis and design of wideband and ultrawideband (UWB) antennas for wireless applications, is presented. Planar, printed, dielectric, and wearable antennas, achievable on laminate (rigid and flexible), and textile dielectric substrates are taken into account. The performances of small, low-profile, and dielectric resonator antennas are illustrated paying particular attention to the application areas concerning portable devices (mobile phones, tablets, glasses, laptops, wearable computers, etc.) and radio base stations. This information provides a guidance to the selection of the different antenna geometries in terms of bandwidth, gain, field polarization, time-domain response, dimensions, and materials useful for their realization and integration in modern communication systems.

scholarly journals Interference Cancellation Based Spectrum Sharing for Massive MIMO Communication Systems

Sensors ◽  
2021 ◽  
Vol 21 (11) ◽  
pp. 3584
Author(s):  
Milembolo Miantezila Junior ◽  
Bin Guo ◽  
Chenjie Zhang ◽  
Xuemei Bai
Keyword(s):  
Interference Cancellation ◽  
Communication Systems ◽  
Spectrum Sharing ◽  
Null Space ◽  
Base Station ◽  
Base Stations ◽  
Small Cells ◽  
Data Traffic ◽  
New Approach ◽  
Lte Advanced

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.

scholarly journals Design and Analysis of Super Wideband Antenna for Microwave Applications

Sensors ◽  
2021 ◽  
Vol 21 (2) ◽  
pp. 477
Author(s):  
Warsha Balani ◽  
Mrinal Sarvagya ◽  
Ajit Samasgikar ◽  
Tanweer Ali ◽  
Pradeep Kumar
Keyword(s):  
Communication Systems ◽  
Equivalent Circuit Model ◽  
Wireless Communication Systems ◽  
Impedance Bandwidth ◽  
Frequency Range ◽  
Fractional Bandwidth ◽  
Wide Bandwidth ◽  
Wireless Applications ◽  
Frequency Constraint ◽  
Time Domain Characterization

In this article, a compact concentric structured monopole patch antenna for super wideband (SWB) application is proposed and investigated. The essential characteristics of the designed antenna are: (i) to attain super-wide bandwidth characteristics, the proposed antenna is emerged from a traditional circular monopole antenna and has obtained an impedance bandwidth of 38.9:1 (ii) another important characteristic of the presented antenna is its larger bandwidth dimension ratio (BDR) value of 6596 that is accomplished by augmenting the electrical length of the patch. The electrical dimension of the proposed antenna is 0.18λ×0.16λ (λ corresponds to the lower end operating frequency). The designed antenna achieves a frequency range from 1.22 to 47.5 GHz with a fractional bandwidth of 190% and exhibiting S11 < −10 dB in simulation. For validating the simulated outcomes, the antenna model is fabricated and measured. Good conformity is established between measured and simulated results. Measured frequency ranges from 1.25 to 40 GHz with a fractional bandwidth of 188%, BDR of 6523 and S11 < −10 dB. Even though the presented antenna operates properly over the frequency range from 1.22 to 47.5 GHz, the results of the experiment are measured till 40 GHz because of the high-frequency constraint of the existing Vector Network Analyzer (VNA). The designed SWB antenna has the benefit of good gain, concise dimension, and wide bandwidth above the formerly reported antenna structures. Simulated gain varies from 0.5 to 10.3 dBi and measured gain varies from 0.2 to 9.7 dBi. Frequency domain, as well as time-domain characterization, has been realized to guide the relevance of the proposed antenna in SWB wireless applications. Furthermore, an equivalent circuit model of the proposed antenna is developed, and the response of the circuit is obtained. The presented antenna can be employed in L, S, C, X, Ka, K, Ku, and Q band wireless communication systems.

scholarly journals Non-Line-of-Sight Error Mitigation in Wireless Communication Systems

2011 ◽  
Vol 1 ◽  
pp. 173-177
Author(s):  
Szu Lin Su ◽  
Yi Wen Su ◽  
Ho Nien Shou ◽  
Chien Sheng Chen
Keyword(s):  
Communication Systems ◽  
Hybrid Methods ◽  
Mobile Station ◽  
Base Stations ◽  
Superior Performance ◽  
Line Of Sight ◽  
Time Of Arrival ◽  
Angle Of Arrival ◽  
Error Statistics ◽  
Non Line Of Sight

When there is non-line-of-sight (NLOS) path between the mobile station (MS) and base stations (BSs), it is possible to integrate many kinds of measurements to achieve more accurate measurements of the MS location. This paper proposed hybrid methods that utilize time of arrival (TOA) at five BSs and angle of arrival (AOA) information at the serving BS to determine the MS location in NLOS environments. The methods mitigate the NLOS effect simply by the weighted sum of the intersections between five TOA circles and the AOA line without requiring priori knowledge of NLOS error statistics. Simulation results show that the proposed methods always give superior performance than Taylor series algorithm (TSA) and the hybrid lines of position algorithm (HLOP).

scholarly journals Energy Optimization of a Laser-Powered Hovering-UAV Relay in Optical Wireless Backhaul

2021 ◽  
Author(s):  
Muhammad Salman Bashir ◽  
Mohamed-Slim Alouini
Keyword(s):  
Quality Of Service ◽  
Communication Systems ◽  
Low Cost ◽  
Base Stations ◽  
Achievable Rate ◽  
Optical Wireless ◽  
Free Space Optical ◽  
Decode And Forward ◽  
Wireless Backhaul

<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>

scholarly journals On the Security of LEO Satellite Communication Systems: Vulnerabilities, Countermeasures, and Future Trends

2022 ◽  
Author(s):  
Pingyue Yue ◽  
Jianping An ◽  
Jiankang Zhang ◽  
Gaofeng Pan ◽  
Shuai Wang ◽  
...  
Keyword(s):  
Communication System ◽  
Communication Systems ◽  
Satellite Communication ◽  
Future Trends ◽  
Comprehensive Review ◽  
Satellite Communication System ◽  
Development Status ◽  
System A ◽  
Leo Satellite

<div>In view of the development status of the security of LEO satellite communication system, a comprehensive review, induction, and summary is carried out.<br></div>

Cooling technologies for data centres and telecommunication base stations – A comprehensive review

2021 ◽  
pp. 130280
Author(s):  
Yelong Zhang ◽  
Yanqi Zhao ◽  
Siyuan Dai ◽  
Binjian Nie ◽  
Hongkun Ma ◽  
...  
Keyword(s):  
Base Stations ◽  
Comprehensive Review ◽  
Data Centres
Sign in / Sign up

Export Citation Format

Share Document