Kompakte lae-verlies diplekser met gestapte transmissielyn resoneerder

Anthonissen, Lukas Willem (1993)

Tesis (M. Ing.) -- Universiteit van Stellenbosch, 1993.

Thesis

ENGLISH ABSTRACT: The design of a compact narrowband UHF diplexer involves a complicated network synthesis problem. The complexity of the synthesis problem, in particular the diplexing of two signal paths to achieve a three port network, renders conventional exact approximations insufficient. Recent advances in computer aided network optimization facilities a synthesis procedure whereby an approximate set of element values can be optimized to achieve an exact network. Conventiona UHF resonators were assessed for mechanical stability, low losses and ease of implementation. This resulted in the development of a coaxial resonator that supports two modes of resonance. An approximate synthesis procedure is presented whereby resonators in a coupled resonator bandpass prototype are replaced by modified resonators suitable for implementation in a coaxial structure. The resultant filter is of a compact dimensions with exceptional attenuation characteristics near the passband. An approximate model was developed for the losses in a stepped transmission line resonator. This approximation was verified by practical measurements. A compact narrowband filter was implemented. The results of practical measurements are included.

AFRIKAANSE OPSOMMING: Die ontwerp van 'n nouband UHF-diplekser behels 'n ingewikkelde netwerksintese probleem. Weens die kompleksiteit van die sinteseprobleem, veral die dipleksering van twee seinpaaie om 'n driepoortnetwerk te vorm, is konvensionele eksakte benaderings selde voldoende. Die huidige ontwikkeling op die gebied van rekenaargesteunde netwerkoptimering vergemaklik 'n sintese waarvolgens 'n benaderde stel elementwaardes gebruik word om 'n eksakte netwerk deur optimering te verkry. Konvensionele UHF-resoneerders is ondersoek vir meganiese stabiliteit, verliese en implementeerbaarheid. Die gevolg hiervan is die bekendstelling van 'n koaksiale resoneerder wat twee modusse van resonansie ondersteun. 'n Netwerksintese benadering word aangebied waarvolgens resoneerders in 'n gekoppelde resoneerder banddeurlaatprototipe vervang word met aangepaste resoneerders geskik vir implementering in 'n koaksiale struktuur. Die resultaat is 'n filter van kompakte afmetings met besonder goeie verswakkingseienskappe naby die deurlaatband. 'n Benaderde model vir die verliese in 'n gestapte transmissielyn struktuur is ontwikkel. Hierdie benadering is geverifieer met die resulate van 'n praktiese opmeting. 'n Kompakte nouband filter is geïmplimenteer. Praktiese resultate word ingelsuit.

Please refer to this item in SUNScholar by using the following persistent URL: http://hdl.handle.net/10019.1/58024
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