Stellenbosch University
EE Eng
A configuration of composite resonators consisting of three split-ring resonators is proposed to obtain a triple-band response with two transmission zeros between the passbands. Two new topologies are presented to design triple-band... more
Two macromodeling techniques using rational bases are investigated to accurately predict the natural frequencies of highly resonant microwave structures. Three methods are proposed and compared to calculate pole-free solutions to the... more
Interpolation models are used in computational electromagnetic (CEM) analysis techniques to provide highly accurate models for microwave devices. In this article the use of a Thiele-type adaptive rational interpolation formulation is... more
be significant not only for rectangular microstrip patches over ground planes without apertures, but also for rectangular microstrip patches over ground planes with rectangular apertures. Other results also have indicated that... more
An in situ tunable diode mounting topology for waveguide switches is presented and utilized to design and fabricate two evanescent-mode X-band switching modules of approximately 15% and 25% fractional bandwidth. The ability of the... more
Relaxed Vector Fitting is known to be a reliable tool for the macromodeling of noisy frequency reponses. The strength of this method originates from the introduction of a "relaxed" non-triviality condition. In this paper, some... more
A technique is proposed to synthesize the ridge taper of a quadruple-ridged flared horn (QRFH) antenna. By considering the modal propagation in the horn it is possible to improve the antenna performance. A QRFH is designed for an offset... more
- by Petrie Meyer
A dual-mode antenna design, utilizing a combination of differential-and common-mode excitations, is presented. This antenna offers the possibility to complex-combine both modes in order to obtain a near-hemispherical Field of View (FoV)... more
- by Petrie Meyer
A theoretical framework for a mixed differential and common mode sensitivity analysis of active receiving antennas is presented, which includes the derivation of a novel set of noise parameters for dual-mode balanced amplifiers. The... more
A conical quad-mode antenna excited through four orthogonal transverse electromagnetic modes is presented. The radiation characteristics of each mode are validated through measurements, illustrating the complimentary nature of the four... more
- by Petrie Meyer
Vector Fitting is a robust technique for transfer function synthesis in the frequency domain. This method combines the use of a Sanathanan-Koerner iteration and a well-chosen partial fraction basis. It is known that its convergence... more
An equivalent circuit model of a quadraxial feed for ultra-wide bandwidth quadruple-ridged flared horn (QRFH) antennas is presented. The circuit is synthesised by only 3 unknowns and achieves an accurate input impedance for a wide range... more
- by Petrie Meyer
The polarimetric performance of a quad-mode an-tenna element, consisting of a pair of crossed dipoles and an integrated monopole fed by a quadraxial transmission line, is analysed. Results are compared to a conventional dual-polarised... more
- by Petrie Meyer
A quadraxial feed, excited by two orthogonal differential modes, is proposed for ultra wideband quadruple-ridged flared horn (QRFH) antennas that obviates the need for a balun. It is shown that in this configuration the fundamental TE11... more
- by Petrie Meyer
The response of a 96 element quad-mode antenna (QMA) array configured in the layout of a Low Frequency Array (LOFAR) Low Band Antenna (LBA) station is assessed. Mutual coupling between the four fundamental excitation modes of each QMA is... more
- by Petrie Meyer
A new design for a triple-mode resonator based on multiple split-ring resonators is introduced. All three modes exhibit very high unloaded Q-factors ranging from 100 to 240 which is suitable for design of high selectivity filters. This... more
- by Petrie Meyer