Thesis (MScEng)--Stellenbosch University, 2011. / ENGLISH ABSTRACT: This thesis presents the study, analysis and design of electronically tunable filters, that can be tuned over a wide
frequency range (20-500MHz), for use in a direct sampling receiver. The final design does not have to be a
single filter, but may be comprised of a filter bank which enables switching between the filters. The band of
interest is too low to use normal transmission lines and lumped elements have to be used. Different topologies
that can implement Coupled Resonator filters with lumped elements are investigated. Devices that can be used
for tuning are also investigated and varactor diodes are found to be the most suitable tuning devices currently
available. Two filters, one at the high-end and one at the low-end of the band, were designed and built, both
using varactor diodes. These filters perform well in terms of tuning range, but achieving low losses with current
technologies in this band remains difficult. / AFRIKAANSE OPSOMMING: Hierdie tesis meld die studie, analise en ontwerp van elektronies verstelbare filters, wat verstelbaar is oor ’n
wye band (20-500MHz), vir gebruik in ’n direk-monster-ontvanger. Die finale ontwerp hoef nie ’n enkele filter
te wees nie, maar kan bestaan uit ’n filterbank wat skakeling tussen die filters toelaat. Die betrokke band is
te laag vir die gebruik van normale transmissielyne en diskrete komponente moet gebruik word. Verskillende
topologieë wat gekoppelde resoneerder filters implementeer met diskrete komponente is ondersoek. Verstelbare
komponente word ook ondersoek en varaktor diodes blyk die mees geskikte verstelbare komponent wat huidig
beskikbaar is in hierdie band. Twee filters, een aan die hoë kant en een aan die lae kant van die band, is ontwerp
en gebou, beide met varaktor diodes. Hierdie filters het wye verstelbare bereik, maar dit is steeds moeilik om
verliese te beperk met die huidige tegnologie.
| Identifer | oai:union.ndltd.org:netd.ac.za/oai:union.ndltd.org:sun/oai:scholar.sun.ac.za:10019.1/17966 |
| Date | 12 1900 |
| Creators | Terblanche, Phillip |
| Contributors | Meyer, P., De Villiers, D. I. L., Stellenbosch University. Faculty of Engineering. Dept. of Electrical and Electronic Engineering. |
| Publisher | Stellenbosch : Stellenbosch University |
| Source Sets | South African National ETD Portal |
| Language | en_ZA |
| Detected Language | Unknown |
| Type | Thesis |
| Format | 89 p. : ill. |
| Rights | Stellenbosch University |
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