Browsing by Author "Maas, Susan"
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- ItemCoaxial resonator filters(Stellenbosch : Stellenbosch University, 2011-12) Maas, Susan; Meyer, P.; Van der Walt, P. W.; Stellenbosch University. Faculty of Engineering. Dept. of Electrical and Electronic Engineering.ENGLISH ABSTRACT: The purpose of this project is to develop a number of coaxial resonator lters. Firstly, the theoretical model of the lter is discussed, with a Tchebyscheff LC-ladder prototype lter used to derive a generalised bandpass lter. From this, generalised Combline- and Interdigital lters are derived. Following this, various options and limitations in the mechanics of microwave lters are discussed. Results are shown for an in-depth study considering the unloaded quality factor for thirteen di erent resonators. Each resonator is unique in the method of manufacturing, polishing, as well as plating. Utilizing the information obtained from the unloaded quality factor measurements, three coupled coaxial resonator lters, are designed for use in a radar system, namely a sixth order 2125 MHz Combline lter, a sixth order 9250 MHz Interdigital lter and a third order 9250 MHz Interdigital lter. Optimal results were obtained when both resonators and coupled transmission line lters were constructed from aluminium that was wire-cut and then silver electroplated.
- ItemMulti-layered substrate integrated Waveguide (MSIW) Waffle-Iron Filters(Stellenbosch : Stellenbosch University, 2019-12) Maas, Susan; Meyer, Petrie; Stellenbosch University. Faculty of Engineering. Dept. of Electrical and Electronic Engineering.ENGLISH ABSTRACT: This dissertation will present the following two topics: (1) Implementation of a waffle-iron filter, utilising multi-layered substrate integrated waveguide (MSIW) technology and (2) Developing a new methodology for measuring scattering parameters of multimode waveguide filters. The classical image impedance synthesis method for waffle-iron filter design is used to develop two filters. Filter A is a classical MSIW Waffle-iron filter and filter B is an extended version with an extra step in the middle of the filter. This work proposes two methods in measuring a multimode waveguide filter; one utilising a set of measurements with different probe positions, and one using a radiating horn. The prototypes presented, displays less than -12 dB passband reflection over 8.5 to 10.5 GHz, with stopband attenuation in excess of 70 dB over the harmonic bands 15 to 43 GHz for filter A and 15 to 48 GHz for filter B. The prototypes were designed to handle 10 Watt average power in the transmitted band. A good correlation is found between synthesised and measured responses in these two designs.