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Reduction of the antenna coupling in a bi-static, FM-CW radar system

Thesis (MScEng)--Stellenbosch University, 2011.

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Main Author: Malan, Frederich T
Other Authors: Palmer, K. D.
Format: Thesis
Language:en_ZA
Published: Stellenbosch : Stellenbosch University 2011
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access_status_str Open Access
author Malan, Frederich T
author2 Palmer, K. D.
author_browse Malan, Frederich T
Palmer, K. D.
author_facet Palmer, K. D.
Malan, Frederich T
author_sort Malan, Frederich T
collection Thesis
dc_rights_str_mv Stellenbosch University
description Thesis (MScEng)--Stellenbosch University, 2011.
format Thesis
id oai:scholar.sun.ac.za:10019.1/18029
institution Stellenbosch University (South Africa)
language en_ZA
last_indexed 2026-06-10T12:46:51.765Z
license_str Other — see source repository
provenance_str_mv Harvested via OAI-PMH from SUNScholar — Stellenbosch University Repository
publishDate 2011
publishDateRange 2011
publishDateSort 2011
publisher Stellenbosch : Stellenbosch University
publisherStr Stellenbosch : Stellenbosch University
record_format dspace
source_str SUNScholar — Stellenbosch University Repository
spelling oai:scholar.sun.ac.za:10019.1/18029 Reduction of the antenna coupling in a bi-static, FM-CW radar system Malan, Frederich T Palmer, K. D. Stellenbosch University. Faculty of Engineering. Dept. of Electrical and Electronic Engineering. Frequency modulated continuous wave (FM-CW) radar systems Transmitter power leakage Low frequency radar Very High Frequency (VHF) band Low coupling Field-programmable gate array Dissertations -- Electronic engineering Theses -- Electronic engineering Thesis (MScEng)--Stellenbosch University, 2011. ENGLISH ABSTRACT: A well-known problem with FM-CW radar systems is the leakage of transmitter power into the receiver which leads to the making of close-in targets, and can severely limit the system dynamic range performance. This thesis considers two solutions to this radar system problem for a low frequency radar operating in the VHF band. The first method to suppress coupling is using separate transmit and receive antennas designed in such a way as to reduce coupling between them. The second is to design a negative feedback loop as part of the radar receiver where the feedback loop adaptively reduces the amount of transmitter leakage through to the receiver. This project details the realisation of these two solutions. A number of antenna designs are modelled in software and simulated to determine their characteristics of which the transmit-to-receive coupling is the key parameter. As no low coupling configuration could be found a simple configuration is chosen and practical measurements are taken. These antennas are then used in the radar system that is to be built. An FM-CW radar system is designed and simulated using software with a negative feedback loop being designed and implemented into the radar simulation. A practical radar system is then made inclusive of the feedback loop. Measurements are then taken to determine the efficacy of the feedback loop. AFRIKAANSE OPSOMMING: ʼn Bekende probleem met FM-CW radar stelsels is die lekkasie van versender krag tot in die ontvanger wat lei tot die maak van nabye teikens en kan die stelsel se dinamiese sendbereik steng beperk. Hierdie tesis oorweeg twee oplossings tot hierdie probleem vir ʼn lae frekwensie radar wat in die VHF band werk. Die eerste metode wat na gekyk word om die koppeling te onderdruk is om die twee antennas van die radar stelsel so te ontwerp sodat die hoeveelheid koppeling tussen hulle verminder is. Die tweede is om ʼn negatiewe terugvoerlus as deel van die ontvanger te ontwerp. Hierdie terugvoerlus sal die versender lekkasie sein aanpassend in die ontvanger verminder. In hierdie projek word die realisering van bogenoemde oplossings uiteengeset. ʼn Paar verskillende antenna ontwerpe word gemodelleer in sagteware en word gesimuleer om hul karakteristieke te bepaal. Die belangrikste van hierdie faktore is die versender na ontvanger koppeling. Sienend dat geen ontwerp met ʼn lae genoeg koppeling gevind kon word nie, is ʼn eenvoudige ontwerp gekies en praktiese metings daarvan geneem. Hierdie antennas word dan gebruik in die radar stelsel wat gebou sal word. ʼn FM-CW radar stelsel word ontwerp en gesimuleer in sagteware. Die negatiewe terugvoerlus word ook ontwerp en geïmplementeer in die radar simulasie. ʼn Praktiese radar stelsel word dan gemaak insluitend die terugvoerlus. Metings word dan geneem om die effektiwiteit daarvan te bepaal. 2011-11-24T09:53:50Z 2011-12-05T13:21:43Z 2011-11-24T09:53:50Z 2011-12-05T13:21:43Z 2011-12 Thesis http://hdl.handle.net/10019.1/18029 en_ZA Stellenbosch University 110 p. : ill. application/pdf Stellenbosch : Stellenbosch University
spellingShingle Frequency modulated continuous wave (FM-CW) radar systems
Transmitter power leakage
Low frequency radar
Very High Frequency (VHF) band
Low coupling
Field-programmable gate array
Dissertations -- Electronic engineering
Theses -- Electronic engineering
Malan, Frederich T
Reduction of the antenna coupling in a bi-static, FM-CW radar system
title Reduction of the antenna coupling in a bi-static, FM-CW radar system
title_full Reduction of the antenna coupling in a bi-static, FM-CW radar system
title_fullStr Reduction of the antenna coupling in a bi-static, FM-CW radar system
title_full_unstemmed Reduction of the antenna coupling in a bi-static, FM-CW radar system
title_short Reduction of the antenna coupling in a bi-static, FM-CW radar system
title_sort reduction of the antenna coupling in a bi static fm cw radar system
topic Frequency modulated continuous wave (FM-CW) radar systems
Transmitter power leakage
Low frequency radar
Very High Frequency (VHF) band
Low coupling
Field-programmable gate array
Dissertations -- Electronic engineering
Theses -- Electronic engineering
url http://hdl.handle.net/10019.1/18029
work_keys_str_mv AT malanfredericht reductionoftheantennacouplinginabistaticfmcwradarsystem