Single-layer dual-wide-band frequency selective surfaces for Wi-Fi blocking in the built environment
department or school: Applied Science, Faculty of
department or school: Engineering, School of (Okanagan)
data provider: DSpace
degree campus: UBCO
creator: Jawad, Nibirh
issued: 2019-02-19T16:43:42Z
issued: 2019
related degree: Master of Applied Science - MASc
degree grantor: University of British Columbia
description: The use of Wi-Fi networks to access the information on the internet has seen a phenomenal increase in recent times. With the large volume of traffic being transmitted, the amount of confidential information has also increased. Yet access to Wi-Fi networks is only secured through password protection. An improvement in technology used to gain unauthorized access has lead to a concern over information security. One possible way of providing increased security to the Wi-Fi networks is by physically limiting the network to a fixed space. Wi-Fi signals can be contained to a built environment through the use of frequency selective surfaces (FSS) in the form of a Wi-Fi blocking wallpaper. An FSS is a conductive periodic pattern in a 2D array. It is able to selectively block or pass electromagnetic waves. Through careful design it should be possible to produce an FSS which is able to block the two Wi-Fi communication bands. In this thesis we present a analysis of various band stop FSS to reach a design with a high stop band bandwidth. We then modify the design to produce a second stop band at a higher frequency. The two stop bands are designed to be at the same ratio as the Wi-Fi communication bands. Two of the designs are fabricated to verify the performance in experiment. The presence of dielectric substrates and the incident angle of waves are known to modify the performance of FSS. Experiments are carried out to quantify these effects and compensate for them in simulations. A simulation method is developed which can closely predict the performance of the design under real-world conditions. The design with the best performance out of the simulated dual band-stop structures is the interdigitated double hexapole and it shows a -20 dB bandwidth of 24.75% and 10.5% in the first and second stop bands respectively. It is able to cover the entire Wi-Fi spectrum giving a minimum attenuation of -34.1 dB across the 2.4 GHz and -29.24 dB across the 5 GHz Wi-Fi band at normal inciden…
aggregated CHO: https://circle.library.ubc.ca/rest/handle/2429/68378
note: Single-layer dual-wide-band frequency selective surfacesfor Wi-Fi blocking in the built environmentbyNibirh JawadB. Sc. Hons. in Engineering, Bangladesh University of Engineering andTechnology, 2015A THESIS SUBMITTED IN PARTIAL FULFILLMENTOF THE REQUIREMENTS FOR THE DEGREE OFMaster of Applied ScienceinTHE COLLEGE OF GRADUATE STUDIES(Electrical Engineering)The University of British Columbia(Okanagan)February 2019c© Nibirh Jawad, 2019The following individuals certify that they have read, and recommend to the Fac-ulty of Graduate and Postdoctoral Studies for acceptance, the thesis entitled:Single-layer dual-wide-band frequency selective surfaces for Wi-Fi block-ing in the built environmentsubmitted by Nibirh Jawad in partial fulfillment of the requirements for the degreeof Master of Applied Science in Electrical Engineering.Examining Committee:Dr. Loı¨c Markley, Electrical EngineeringSupervisorDr. Kenneth Chau, Electrical EngineeringSupervisory Committee MemberDr. Jonathan Holzman, Electrical EngineeringSupervisory Committee MemberDr. Shahria Alam, Civil EngineeringUniversity ExamineriiAbstractThe use of Wi-Fi networks to access the information on the internet has seen aphenomenal increase in recent times. With the large volume of traffic being trans-mitted, the amount of confidential information has also increased. Yet access toWi-Fi networks is only secured through password protection. An improvement intechnology used to gain unauthorized access has lead to a concern over informationsecurity. One possible way of providing increased security to the Wi-Fi networksis by physically limiting the network to a fixed space.Wi-Fi signals can be contained to a built environment through the use of fre-quency selective surfaces (FSS) in the form of a Wi-Fi blocking wallpaper. An FSSis a conductive periodic pattern in a 2D array. It is able to selectively block or passelectromagnetic waves. Through careful design it should be possible to produce anFSS which is able to block the t…
has type: Thesis/Dissertation
date issued: 2019-05
is shown at: 10.14288/1.0376458
language: eng
degree discipline: Electrical Engineering
provider: Vancouver : University of British Columbia Library
publisher: University of British Columbia
rights: Attribution-NonCommercial-NoDerivatives 4.0 International
rights URI: http://creativecommons.org/licenses/by-nc-nd/4.0/
scholar level: Graduate
type: Text
identifier URI: http://hdl.handle.net/2429/68378