| Research activities |
Research activities cover the areas of antennas and propagation, computer solutions of complex electromagnetic field problems, microwave systems and devices, geophysical remote sensing, electromagnetic compatibility and superconducting circuits.
The division's research activities receive financial support from the National Research Foundation and several companies in the private sector.
Current activities in the field of EM focus on the following: microstrip antennas for satellite communications; spiral antennas for ground penetration and borehole radar; FEM, FDTD and MoM modelling of antennas and wave propagation in complex electromagnetic environments; FEM programme development; wave propagation in the earth and absorbing materials; free-space and near-field measurement techniques, the Karoo Array Telescope (KAT) and the Square Kilometre Array (SKA).
Facilities include a microwave anechoic chamber for antenna measurements, a Gaussian microwave optics test bench for the measurement of material properties and across the board measuring facilities up to 50GHz.
In the field of microwave electronics, research focuses on activities and topics such as the study and measurement of electromagnetic compatibility, low noise and high power amplifiers, filter design, oscillators, high power combiners, microwave dielectric heating, active patch antennas and microwave sensors.
A strong modelling and measurement expertise is available, involving close interaction with local radar and avionics industries.
In the superconducting field emphasis is placed on the design, simulation and fabrication of practical devices such as magnetic field sensors (SQUIDs), superconducting microwave filters and superfast logic switching circuits utilizing Josephson junctions as active building blocks.
Facilities include network and spectrum analysers, a screened room, SQUID magnetometers and a cryogenic measurement system for the evaluation of superconducting devices at temperatures as low as -263 degrees Celsius.
Contact person:
Prof DB Davidson: davidson@sun.ac.za OR Tel: +27-21-808 4458
Some of the focus areas are listed below. |
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Borehole Radar |
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Contact Prof Keith Palmer for more information on this research activity. |
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Computational Electromagnetics |
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Computational Electromagnetics (CEM) is the numerical approximation of Maxwell's equations. It is a crucial enabling technology for radio frequency, microwave and wireless engineering, as well as being a technology in its own right. The three most widely used ‘full-wave’ methods - the Finite Difference Time Domain Method, the Method of Moments, and the Finite Element Method - are studied in the CEM focus area. We interact closely with many of the other focus areas in this field, and maintain a very close relationship with EM Software and Systems, the developers of the 3D EM simulation suite FEKO. This focus area is headed by Prof David Davidson, and a noteworthy recent milestone was the publication of his book Computational Electromagnetics for RF and Microwave Engineering. Visit the Computational Electromagnetics Group website for more information about the group, its publications and current research projects. |
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HF Metrology & Electromagnetic Compatibility |
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High frequency (HF) metrology is concerned with reliable measurements at high frequencies using: a) instruments such as vector network analyzers, spectrum analyzers, power meters and sampling oscilloscopes; b) facilities such as anechoic and reverberation chambers, and open area test sites, and c) sensors such as E-field and B-field sensors, common-mode current probes, Rogowski coils, Bersier probes, etc. A key feature of metrology is that of calibration. In this regard we have active relationships with standards bodies in South Africa and also with the National Institute of Standards and Technology (NIST) in Boulder, Colorado.
General research topics can be seen by looking at current and recent past postgraduate programmes on the postgraduate and bursary pages of
Prof Howard Reader and
Dr Riana Geschke. |
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High Frequency Antennas |
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Contact Prof Keith Palmer for more information on this research activity. |
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Microwave Active Components and Systems |
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This research activity focuses on the design of active components such as low phase noise oscillators and phase-locked loops typically used in radars. High speed multi channel QPSK data transmitters and receivers are developed for satellite applications.
Contact Prof Johann de Swardt for more information on this research activity. |
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Microwave Passive Systems |
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This activity concerns the design, electromagnetic analysis and optimisation of passive microwave circuits such as filters, couplers, combiners etc. In terms of component design, current research focuses on high-power devices at X-band, including power combiners and PIN diode switches, with specific attention to new structures and topologies. Antenna feed design for the Karoo Array Telescope (KAT) is also included in this research. On a systems level, millimetre-wave imaging at 35 and 94GHz has emerged as a strong international focus, due to its applications to security. This research is undertaken on a systems level as well as on device level, with the aim of finding cost-effective solutions to industry problems. In terms of modelling, the focus is on adaptively sampled interpolation-based mathematical models of microwave structures. This type of model can be constructed by using very few electromagnetic analysis points, and can be used to great effect in the optimisation of circuits containing these structures.
Contact Prof Petrie Meyer for more information on this research activity. |
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Superconducting Devices and Sensors |
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Visit the Superconductivity and Nano-Devices (SAND) website for more information. |
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