Thesis (MScEng)--Stellenbosch University, 2000. / ENGLISH ABSTRACT: Recent research has shown that standard substation capacitive voltage transformers (CVTs) and current transformers (CTs) can be used for the measurement of wideband high voltage phenomena by employing these apparatus in a transconductance topology. With this topology the voltage waveform can be obtained by integration of the ground return current in the earth straps of the CVT and the CT. This technique does, however, impose unique requirements on the amplification and integration instrumentation due to large dynamic range requirements and the strict offset specifications required for accurate integration. This thesis describes a programmable, wideband signal conditioning system for high voltage (HV) measurements using the transconductance topology. A suitable system topology, optimised to reduce the problems usually associated with grounding and electromagnetic interference (EMI) in HV environments, is proposed. This system consists of an analog signal conditioning subsystem, a digital signal conditioning subsystem and a high speed serial fibre-optic link. The analog signal conditioning subsystem conditions the signals from a sensor to levels suitable for the digitiser of the digital signal conditioning subsystem. The high bandwidth specification of the application made it necessary to consider both discrete and integrated implementation of the analog signal conditioning subsystem. Based on the simulated and laboratory test results of both implementations, the optimum design was chosen for the developed system. The digital signal conditioning subsystem, which performs the integration, as well as the serial optic-fibre link control logic was implemented using programmable logic array (PLA) technology. The digital data is transmitted across the fibre-optic link. This data is then converted back to an analog signal. Keywords: High voltage measurements, Transconductance topology. / AFRIKAANSE OPSOMMING: Onlangse navorsing het aangetoon dat standaard substasie kapasitiewe spanningstransformators en stroomtransformators gebruik kan word om wyeband hoogspanningsverskynsels te meet deur hierdie apparatuur in 'n transkonduktansie topologie aan te wend. Met hierdie topologie kan die spanningsgolfvorm verkry word deur die integrasie van die aardstrome in die aardverbindings van die kapasitiewe spanningstransformators en stroomtransformators. Hierdie tegniek stel egter unieke vereistes vir die versterkings- en integrasieinstrumentasie te wyte aan groot dinamiese bereik vereistes en die streng afset spesifikasies wat benodig word vir akkurate integrasie. Hierdie tesis beskryf 'n programmeerbare, wyeband seinkondisioneringstelsel vir hoogspanningsmetings deur van die transkonduktansie topologie gebruik te maak. 'n Geskikte stelseltopologie, wat geoptimiseer is om probleme, wat gewoonlik met aarding en elektromagnetiese interferensie in hoogspanningsomgewings geassosieer word, te verminder, is voorgestel. Die stelsel bestaan uit 'n analoog seinkondisioneringsubstelsel, 'n digitale seinkondisioneringsubstelsel en 'n hoëspoed seriële optiese vesel koppelvlak. Die analoog seinkondisioneringsubstelsel kondisioneer die seine vanaf 'n sensor na geskikte vlakke vir die versyferaar van die digitale seinkondisioneringsubstelsel. Die hoë bandwydte spesifikasie van die toepassing vereis die inagneming van beide diskrete en geïntegreerde implementerings van die analoog seinkondisioneringsubstelsel. Gebaseer op gesimuleerde en laboratorium toetsresultate van beide implementerings is die optimale ontwerp vir die ontwikkelde stelsel gekies. Die digitale seinkondisioneringsubstelsel wat die integrasie uitvoer, asook die seriële optiese vesel koppelvlak beheerlogika is geïmplementeer met behulp van programmeerbare logika skikking tegnologie. Die digitale data word gestuur oor die optiese vesel koppelvlak. Hierdie data word dan terug geskakel na 'n analoog sein. Sleutelwoorde: Hoogspanningsmetings, Transkonduktansie topologie.

Thesis (MEng)--University of Stellenbosch, 2000. / ENGLISH ABSTRACT: The Attitude Determination and Control System (ADCS) of the Stellenbosch University Satellite (SUNSAT I) is an integrated system providing some redundancy and the necessary data management to control the spacecraft. However, the redundancy is not easily accessible and there is a lack in flexibility when testing individual modules during integration or when the system needs to be extended. The objective of this thesis was thus to develop a high reliability, flexible, modular communication system that included some type of redundancy to manage real-time data and to prevent severe malfunctioning of the entire system. The first step in the project's development methodology was to summarise the requirements and specifications by studying the current ADCS architecture and data management. An investigation into the Controller Area Network (CAN) protocol showed that this technology would fit the requirements very well, leading to the design and implementation of several concept topologies based on CAN. Thereafter, a demonstration model consisting of three prototype nodes was composed. The performance of the so called dual CAN node was analysed and an extrapolation was 'made to determine whether the architecture could support the complete ADCS. It was demonstrated that the dual CAN node provides enough room to accommodate all the processors, actuators and sensors of the ADCS. At the same time, it was shown that reliability and robustness was increased by enhanced redundancy at a node-level as well as at the greater system-level. A dual CAN bus was provided for redundancy at a node-level. At the system-level, the command and data-gathering modules (ACP or OBC's) can now effectively be multiplexed on the network of actuators and sensors. Furthermore, it was shown that error detection capabilities and diagnostics can be enhanced and the complexity of the communication architecture and related wiring harnesses can be reduced. This allows easier access to modules and simplifies development. / AFRIKAANSE OPSOMMING: Die Attitude Determination and Control System (ADCS) van Stellenbosch University Satellite (SUNSAT I) is 'n geïntegreerde stelsel wat voorsiening maak vir 'n mate van oortolligheid en 'n vermoeë om stelseldata te bestuur vir goeie satellietbeheer. Nietemin, hierdie oortolligheid is nie baie toeganklik nie en daar is 'n gebrek aan aanpasbaarheid tydens die toets en integrasie van individuele modules of moontlike stelseluitbreidings. Die doelwit van hierdie tesis was dus die ontwikkeling van 'n betroubare, aanpasbare, modulêre kommunikasie stelsel wat 'n tipe oortolligheid insluit sodat intydse data bestuur kan word en algehele stelselondergang vermy kan word. Die eerste stap in die projek se ontwikkelings metodiek was om 'n opsomming te verkry van die vereistes en spesifikasies deur die huidige ADCS se argitektuur en databestuur te ondersoek. 'n Ondersoek na die Controller Area Network (CAN) protokol het getoon dat hierdie tegnologie aan baie van die vereistes voldoen. Dit het aanleiding gegee tot die ontwerp en implementering van 'n paar konsep ontwerpe gebaseer op CAN. Daarna is 'n demonstrasie model bestaande uit drie prototipe nodusse gebou. Die werksverrigting van die sogenoemde dual CAN node, is ondersoek en 'n ekstrapolasie was gemaak om vas te stelof die argitektuur die volkome ADCS kan huisves. Deur demonstrasie was daar getoon dat die dual CAN node wel genoeg ruimte verskaf om al die verwerkers, aktueerders en sensors van die ADCS te akkommodeer. Daar was terselfdertyd getoon dat betroubaarheid en robuustheid verhoog is deur die verbeterde oortolligheid op 'n node-vlak sowel as op die groter stelsel-vlak. 'n Dubbele CAN bus is gebruik vir oortolligheid op 'n node-vlak. Op 'n stelsel-vlak kan die bevel-en-dataversamelings modules (ACP en aBC's) effektief gemultipleks word op die netwerk van aktueerders en sensors. Daar was verder getoon dat die foutopspoorings vermoeë en diagnostiese vermoeë verbeter kan word en die kompleksiteit van die kommunikasie argitektuur en ooreenkomstige kabelharnasse vereenvoudig kan word. Die gevolg is vereenvoudigde toegang tot modules en vergemaklikde opgradering.

Thesis (MEng)--University of Stellenbosch, 2000. / ENGLISH ABSTRACT: The need for a locally manufactured, cost-effective, fuel management system led to the design and development of a functional prototype. This thesis presents the design, development and full implementation of two functional prototypes. While field tests performed on the first prototype assisted in identifying necessary modifications, a need for greater complexity in support hardware was also identified. In order to comply with the cost-effective nature of the project, it was realized that this complexity could only be achieved via the implementation of a CPLD based system. Using Altera's Maxplus II design software, the CPLD code was synthesized according to the required specifications then simulated and analyzed On completion of the new CPLD based system, the second prototype, one of Altera's megacore functions is implemented and used as a substitute to an external hardware. All necessary modifications were successfully completed and the system was installed. / AFRIKAANSE OPSOMMING: Die benodiging van 'n lokale vervaardigde, koste effektiewe brandstofbeheerstelsel het gelei tot die ontwerp en ontwikkeling van 'n funksionele prototipe. Hierdie tesis dek die ontwerp, ontwikkeling en volle implementasie van twee funksionele prototipes. Terwyl toetse op die eerste prototipe gebruik is om die nodige aanpassings te identifiseer, is daar ook besef dat daar meer komplekse hardeware onderstuening benodig word. Om die koste effektiewe aard van die projek te handhaaf, is daar gesien dat die nodige kompleksieteit alleenlik deur middel van die implementering van 'n 'CPLD' gebaseerde sisteem bereik kan word. Deur gebruik te maak van Altera se Maxplus II ontwerp sagteware, is die 'CPLD' kode met die nodige spesifiekasies gesintiseer, gesimuleer en geanaliseer. Na voltooing van die tweede prototiepe, die 'CPLD' gebaseerde sisteem, is een van Altera se megacore funksies geimplementeer en gebruik as 'n plaasvervanger vir eksteme hardware. AIle nodige aanpassings is suksesvol voltooi en die sisteem is geinstalleer.

Thesis (MEng)--University of Stellenbosch, 2000. / ENGLISH ABSTRACT: Handwritten signature verification (HSV) is the process through which handwritten signatures are analysed in an attempt to determine whether the person who made the signature is who he claims to be. Banks and other financial institutions lose billions of rands annually to cheque fraud and other crimes that are preventable with the aid of good signature verification techniques. Unfortunately, the volume of cheques that are processed precludes a thorough HSV process done in the traditional manner by human operators. It is the aim of this research to investigate new methods to compare signatures automatically, to eventually speed up the HSV process and improve on the accuracy of existing systems. The new technology that is investigated is the use of the so-called hidden Markov models (HMMs). It is only quite recently that the computing power has become commonly available to make the real-time use of HMMs in pattern recognition a possibility. Two demonstration programs, SigGrab and Securitlheque, have been developed that make use of this technology, and show excellent improvements over other techniques and competing products. HSV accuracies in excess of99% can be attained. / AFRIKAANSE OPSOMMING: Handgeskrewe handtekening verifikasie (HHV) is die proses waardeur handgeskrewe handtekeninge ondersoek word in 'n poging om te bevestig of die persoon wat die handtekening gemaak het werklik is wie hy voorgee om te wees. Banke en ander finansiele instansies verloor jaarliks biljoene rande aan tjekbedrog en ander misdrywe wat voorkom sou kon word indien goeie metodes van handtekening verifikasie daargestel kon word. Ongelukkig is die volume van tjeks wat hanteer word so groot, dat tradisionele HHV deur menslike operateurs 'n onbegonne taak is. Dit is die doel van hierdie navorsmg om nuwe metodes te ondersoek om handtekeninge outomaties te kan vergelyk en so die HHV proses te bespoedig en ook te verbeter op die akkuraatheid van bestaande stelsels. Die nuwe tegnologie wat ondersoek is is die gebruik van die sogenaamde verskuilde Markov modelle (VMMs). Dit is eers redelik onlangs dat die rekenaar verwerkingskrag algemeen beskikbaar geraak het om die intydse gebruik van VMMs in patroonherkenning prakties moontlik te maak. Twee demonstrasieprogramme, SigGrab en SecuriCheque, is ontwikkel wat gebruik maak van hierdie tegnologie en toon uitstekende verbeterings teenoor ander tegnieke en kompeterende produkte. 'n Akkuraatheid van 99% of hoer word tipies verkry.

Thesis (MEng)--University of Stellenbosch, 2000. / ENGLISH ABSTRACT: In this thesis we addressed some issues concerning the automation of the detection, processing and the analysis of gravitational microlensing events, which are currently being used in the search for extra-solar planets. We were provided with a series of data images containing a microlensing event. Using these images we address several practical problems: registration, background subtraction and some PSF modelling. Registration is accomplished by using the intersection points of circular arcs drawn around stellar objects. After which the influence of the sky background is removed by using the watershedding algorithm and plane fitting. Our analysis is based on relative brightness - to counter seeing, the brightness of stars are calculated by isolating the objects from the background and summing over the area. A brightness variation curve is plotted and the trend of the lensing event and the posi tion of a blip are extracted using wavelets, calculating general trends and LOESS. The trend of the brightness variation curve can be used for both identification and classification of various events. It can also be used for the identification and classification of variable stars. Blip analysis is used to detect the presence of a planet (or dark body) in the vicinity of the source. / AFRIKAANSE OPSOMMING: Hierdie tesis beskryf tegnieke om die identifikasie, prosessering en analise van gravitasie mikro-lens gebeure te outomatiseer. Die analise van hierdie gebeure is belangrik aangesien dit gebruik word vir die opsporing van planete buite ons sonnestelsel. Om gebruik te maak van 'n reeks beelde wat een van hierdie gebeure vertoon moet ons die volgende probleme aanspreek: beeld registrasie, verwydering van die agtergrond en die modulering van die verspreiding van die lig van 'n puntbron deur die atmosfeer. Ons verkry registrasie deur die berekening van die snypunte van sirkels met middelpunte by sekere voorwerpe op die beeld. Na registrasie kan ons die invloed van die agtergrond bepaal deur gebruik te maak van die waterskeidingsalgoritme. Dit stelons in staat om die relatiewe helderheid van die voorwerpe ondersoek deur die voorwerpe te isoleer en te sommeer oor die area van 'n voorwerp. 'n Grafiese voorstelling van die helderhede dui vir ons die relatiewe variasies in die helderhede van die mikrolens objek tussen die beelde aan. Ons ondersoek die vorm van die kromme asook die moontlike voorkoms van 'n 'blip' deur middel van wavelet analiese en die LOESS metode. Die vorm van die kromme word gebruik vir die identifikasie en klassifikasie van die verskillende mikro-lens gebeure en kan uitgebrei word om ook veranderlike sterre te ondersoek. Die teenwoordighied van 'n 'blip' op die data wys op die moontlik teenwoordigheid van 'n planeet nabyaan die bron wat ons ondersoek.

Thesis (MScEng)--University of Stellenbosch, 2001. / ENGLISH ABSTRACT: This thesis describes the study of two soft-switching inverter topologies that are well suited to high-power applications. For the first topology, namely an active resonant turn-off snubber, the existing theory is expanded with a detailed study into operation strategies and topology protection. This is followed by an investigation into the second topology, which is a combined snubber that reduces both turn-off and turn-on losses. The investigation involves a detailed analysis of the losses in the snubber components and main devices, as well as a study into the effects of parasitic components and diode reverse recovery on the operation of the snubber. Based on this theory a snubber optimisation procedure is also developed. Possible operation strategies and protection techniques were also evaluated for this topology. Single-phase experimental inverters were used to verify the basic operation theory and switching loss prediction for both topologies. The thesis is concluded by the design and construction of a practical soft-switching threephase inverter. After implementation the experimental inverter is used for theory verification. / AFRIKAANSE OPSOMMING: Hierdie proefskrif beskryf die ondersoek na twee saggeskakelde omsetter topologieë wat veral geskik is vir hoë-drywing toepassings. Die bestaande teorie aangaande die eerste topologie, naamlik 'n aktiewe, resonante, afskakel gapser, word uitgebrei met 'n deeglike-studie oor bedryfstegnieke en beskermingsmetodes. Vervolgens word 'n gekombineerde gapser topologie, wat beide aanskakel- en afskakelverliese verminder, ondersoek. Die studie behels 'n volledige analise van die verliese in die omsetter en gapser komponente en die invloed van parasitêre komponente en diode tru-herstel. Hierdie teorie word ook gebruik om 'n optimale gapser ontwerp prosedure te ontwikkel. Die moontlikke bedryfstegnieke en beskermingsmetodes word ook vir hierdie topologie evalueer. In albei gevalle is eksperimentele, enkelfase omsetters gebruik om die teorie oor basiese werking en skakelverlies vermindering te verifieer. Die ondersoek word afgesluit deur die ontwerp en konstruksie van 'n praktiese, saggeskakelde, drie-fase omsetter te beskryf. Na implimentering van die omsetter word volledige eksperimentele verifikasie uitgevoer.

Thesis (MScEng)--University of Stellenbosch, 2001. / ENGLISH ABSTRACT: The aim of the thesis is the design of an economical do - it - yourself ground station for school pupils to communicate with SUNSAT 1. The ground station should also be more economical than a hand - held transceiver radio. The do - it - yourself requirement is there to arouse an interest in electronics, radio frequency electronics and satellite communications in school pupils. A system-level design was done for a ground station consisting of modules which may be bought individually as do - it - yourself kits to eventually produce a full set. The modules are a VHF receiver, a VHF transmitter, a UHF down converter and a modem. Each module has functions which aid in the process of communications (data as well as voice) between the satellite and the ground station. A VHF receiver was designed and implemented to be capable of receiving RF signals from SUNSAT 1. A crystal controlled oscillator was designed that oscillates with a frequency tolerance of less than or equal to ± 0.003 % when aligned without the necessary IlF equipment. An economical Broadband Signal Generator was implemented with a 74ACT14 logic IC, which may be used to align the receiver. The higher harmonics of a square wave with a fundamental frequency of 4 kHz are used as a RF source. A sound card was utilised as a modem to receive 1200 baud AFSK (AX.25 protocol) data and the software was also used to display the data on PC. The data was transmitted from another ground station / AFRIKAANSE OPSOMMING: Die doel van die tesis is die ontwerp van 'n ekonomiese doen - dit - self - grondstasie vir skoolkinders om met SUNSAT I te kan komunikeer. Die grondstasie moet ook meer ekonomies wees as 'n handstelradio. Die doel van die doen - dit - self - beginsel is om die belangstelling in elektronika, RF elektronika and satelliete by skoolkinders aan te moedig. 'n Stelsel ontwerp van 'n grondstasie is gedoen wat bestaan uit modules wat afsonderlik as doen - dit - self - modules aangeskaf kan word om so tot 'n totale grondstasie op te bou. Die modules is die "VHF" - ontvanger, "VHF" - sender, UHF - afmenger en 'n modem. Elke module verskaf funksies wat bydra om met SUNSAT I te kan kornmunikeer. 'n VHF - ontvanger wat in staat is om RF - seine vanaf SUNSAT I te ontvang is ontwerp en gebou. 'n Kristal b heerde ossillator is ontwerp met 'n frekwensie toleransie van kleiner en gelyk aan ± 0.003 % wanneer dit ingestem word sender die nodige RF toerusting. 'n Ekonomiese wyeband - seingenerator is gemplementeer met 'n 74ACT14 logiese vlokkie om as 'n RF - bron gebruik te word om die ontvanger in te stel. Die boonste (hoer) harmoniek van die 4 kHz vierkantsgolf word as 'n "RF bron" gebruik. 'n Klankkaart is suksesvol gebruik as 'n modem om 1200 baud AFSK data (AX.25 protokol) te ontvang en die data met die nodige sagteware op 'n skerm te vertoon. Data is uitgcstuur vanaf 'n ander grondstasie.

Thesis (MEng)--University of Stellenbosch, 2001. / ENGLISH ABSTRACT: This thesis describes the development of a distributed ground support system to be used in the small satellite program at the University of Stellenbosch. A literature study was done to determine the current trends in ground support design. These trends are presented together with an analysis of the SUNSAT groundstation software. New technologies in the field of distributed systems are discussed and used in the design of a distributed ground support system. The design centres around a servicesbased architecture where services are distributed on the network. The design is evaluated according to attributes exhibited by effective distributed systems. Certain services were implemented to demonstrate the feasibility of the design. The implementations are discussed and suggestions are made for future improvements and fields of possible further study. / AFRIKAANSE OPSOMMING: Hierdie tesis beskryf die ontwikkeling van 'n verspreide-grondstasie-sisteem vir gebruik in die Universiteit van Stellenbosch se satelliet-program. Eerstens is 'n literatuurstudie gedoen om die huidige verwikkelinge in die veld van satellietondersteuning-ontwikkeling vas te stel. Hierdie verwikkelinge word bespreek en gebruik om die SUNSAT-grondstasie sagteware te evalueer. Nuwe tegnologieë in die veld van verspreide stelsels word ondersoek en bespreek. Die ontwerp van die grondstasie is gebaseer op 'n verspreide dienste argitektuur. Die ontwerp word beskryf en geëvalueer aan die hand van kenmerke tipies van 'n effektiewe verspreide stelsel. Om die werkbaarheid van die ontwerp te toon, is sekere van die dienste geïmplimenteer, en die funksionering daarvan word bespreek. Voorstelle word ook gemaak oor moontlike toekomstige navorsing wat gedoen kan word.

Thesis (MScEng)--University of Stellenbosch, 2001. / ENGLISH ABSTRACT: One of the problems with any deep space communication system is that information may be altered or lost during transmission due to channel noise. It is known that any damage to the bit stream may lead to objectionable visual quality distortion of images at the decoder. The purpose of this thesis is to design an error correction and data compression algorithm for image protection, which will allow the communication bandwidth to be better utilized. The work focuses on Sunsat (Stellenbosch Satellite) images as test images. Investigations were done on the JPEG 2000 compression algorithm's robustness to random errors, putting more emphasis on how much of the image is degraded after compression. Implementation of both the error control coding and data compression strategy is then applied to a set of test images. The FEe algorithm combats some if not all of the simulated random errors introduced by the channel. The results illustrates that the error correction of random errors is achieved by a factor of 100 times (xl00) on all test images and that the probability of error of 10-2in the channel (10-4for image data) shows that the errors causes little degradation on the image quality. / AFRIKAANSE OPSOMMING: Een van die probleme met kommunikasie in die ruimte is dat informasie mag verlore gaan en! of gekorrupteer word deur ruis gedurende versending deur die kanaal. Dit is bekend dat enige skade aan die bisstroom mag lei tot hinderlike vervorming van die beelde wat op aarde ontvang word. Die doel van hierdie tesis om foutkorreksie en datakompressie te ontwikkel wat die satelliet beelde sal beskerm gedurende versending en die kommunikasie kanaal se bandwydte beter sal benut. Die werk fokus op SUNSAT (Stellenbosch Universiteit Satelliet) se beelde as toetsbeelde. Ondersoeke is gedoen na die JPEG2000 kompressie algoritme se bestandheid teen toevalsfoute, met klem op hoeveel die beeld gedegradeer word deur die bisfoute wat voorkom. Beide die kompressie en die foutkorreksie is ge-implementeer en aangewend op die toetsbeelde. Die foutkorreksie bestry die gesimuleerde toevalsfoute, soos wat dit op die kanaal voorkom. Die resultate toon dat die foutkorreksie die toevalsfoute met 'n faktor 100 verminder, en dat 'n foutwaarskynlikheid van 10-2 op die kanaal (10-4 op die beelddata) weinig degradering in die beeldkwaliteit veroorsaak.

Thesis (MScEng)--University of Stellenbosch, 2001. / ENGLISH ABSTRACT: An antenna for ground level deployed Ground Penetrating Radar applications is presented. The antenna is matched to the ground via a low impedance dielectric matching section improving the radiation pattern and input impedance characteristics. A bowtie antenna was used for the design with the edges rounded to stabilize the resonant frequency. The radiation pattern was focused to the one side of the antenna for ground penetration using a non-absorptive metallic cylindrical air filled cavity. Edge reflections from the antenna were reduced by means of discrete resistor terminations between the antenna and the cavity. A wire equivalent of the solid metallic antenna was investigated giving similar characteristics to that of the solid antenna. The radiation pattern deformation arising from transmitting a wave from an antenna in air into the ground due to the impedance mismatch was investigated. This was overcome with the use of a polypropylene dielectric slab inserted between the antenna and the ground. Together with improving the radiation pattern the antenna was less sensitive to ground parameter variations and to an air gap introduced between the slab and the ground. This was implemented as a wheel mounted system with adjustable height settings depending on the terrain. A pair of mounted antennas was constructed to be tested on an existing bistatic Stepped Frequency Continuous Wave radar operating in the 50-400 MHz band developed by the University of Cape Town. This antenna is seen as providing a solution to the problem of coupling an antenna to a low wave impedance medium such as ground. / AFRIKAANSE OPSOMMING: 'n Antenne word vir Grond Penetrerende Radar toepassings voorgestel. Dit is spesifiek ontwikkel vir oppervlak ontplooide stelsels ontwerp. Die antenne is aangepas tot die grond deur middel van 'n diëlektriese aanpassingseksie wat die starlingspatroon en intree-impedansie karakteristieke verbeter. Die antenne is tot die grond toe aangepas deur middel van 'n diëlektriese aanpassingseksie wat die starlingspatroon en intree-impedansie karakteristieke verbeter. 'n Strikdas antenne was gebruik vir die ontwerp, met die kante gerond om die resonante freqwensie te stabiliseer. Om die stralingspatroon van die antenne na een kant toe te fokus was 'n nie-absorbeerede metaleiese, luggevulde, silindriese holte daaragter geplaas om die energie vorentoe te weerkaats. Weerkaatsings van die rand van die antenne word onderdruk met behulp van koppelende weerstande tussen die antenne en die holte. A draad ekwivalent van die antenne was ook ondersoek met goeie ooreenstemming met die soliede strikdas. Die impedansie wanaanpassing wat ontstaan as 'n antenne wat in lug is, in die grond in straal veroorsaak dat die stralingspatroon van die antenne vervorm word. Dit was gevind dat deur 'n aanpassings blad van 'n diëlektriese materiaal, naamlik polipropileen, gebruik te maak tussen die antenne en die grond dat dit die probleem oplos. Saam met dit was gevind dat die antenne minder sensitief was vir veranderings in grondparameters en ook vir 'n lug gaping tussen die blad en die grond. Die het gemaak dat die antenne op wiele gemonteer kon word met verstelbare hoogte afhangend van die terrein. 'n Stel geskaleerde antennes was gemaak om op 'n beskikbare bistatiese Trap Frekwensie Kontinue Golf radar te werk. Dit werk oor die 50-400 MHz band en was ontwikkel deur die Universitiet van Kaapstad. Die antenne word gesien as 'n oplossing vir antenne koppelingsprobleme ondervind by laë golf impedansie materiale.