Computer-modelling of rf-components has a long tradition and is meanwhile integral part of any research and development activity in universities, laboratories and industry. A wide range of numerical methods has been excessively developed such as volumetric discretization methods (FE: Finite Elements, FD: Finite Difference, FI: Finite Integration, FV: Finite Volume, TLM: Transmission Line Method, etc.) and surface discretization algorithms (BEM: Boundary Element Method, MM: Moment Method: MM: Multipole Method, etc.). In view of the large variety of different methods, many of which are developed towards a mature stage, it becomes more and more important to select the right algorithm for any given application. The presentation will give an overview of the state of the art in modelling rf-components, an approach to classify the algorithms with respect to their effectiveness for certain applications as well as a view into the future of research direction in the field of numerical modelling.

In reviewing the achievements of South Africa (SA) in electromagnetics (EM), it is interesting to consider the past to explain the present. We sketch a few key South African events in the field over approximately a century [1-10]. We then identify and discuss contemporary activities in industry, research institutions and academia. Two of these activities, the Karoo Array Telescope (KAT) and the application of a widely-used computational EM code, are highlighted as representative demonstrations of SA's current research and development. We also present some specific work within our own department which we are able to describe in more depth. These subjects are chosen to reflect topical EM problems. TABLE I: EM Time-lines in South Africa 1890s-1920 Wireless in Anglo-Boer War (1899-1902); Hendrik van der Bijl's pioneering work on thermionic vacuum tubes (1913). 1930s Otto Brune (1930) - important work laying foundation for modern network theory; Bernard Price Institute (1937) - important lightning research; First application of remote-sensing for sub-surface geology in SA. 1939- South African radar in World War II 1945 CSIR (Council for Scientific and Industrial Research) founded 1954 Trevor Wadley’s Tellurometer 1960s Martin Wedepohl power line carrier modelling; Rocket Research Institute (CSIR) sends engineers & scientists overseas to study astronautics, radar and missiles; Establishment of National Institute for Defence Research (division of CSIR; FV Ashpole /JJ du Plessis/LL van Zyl); SANAE built in Antartic 1970s NIDR Paardefontein Microwave Antenna Range (JH Cloete / DE Baker) was developed, first anechoic chamber built and computational EM codes (DA McNamara) began; Filters, Components and EM (JAG Malherbe, Stellenbosch Univ); Academic / Industry connection made by HL Nattrass / HC Viloen / L v Biljon. GD Nicholson got HartRAO established (1975) as national Radio Astronomy (RA) facility. Late 70s into 80s DC Baker and Poole's (AWV and LMG) involved in propagation prediction and radio astronomy. 1980s SAIEE Antennas and Propagation first symposium, SA Section of IEEE 1985, AP-MTT local chapter formed; The FRD's (Foundation for Research and Development) Microwave Engineering programme (JH Cloete, PW van der Walt, Stellenbosch Univ) and EM programme (JAG Malherbe, Pretoria Univ); Compact Range at Pretoria Univ, first HP8510 Automatic Network Analyzer and travelling-wave tube programme (HL Nattrass, Natal Univ); Microwave systems/circuits programme / Radar Remote Sensing Group (BJ Downing / MR Inggs, Cape Town Univ); several EM related companies founded. 1990s Further EM related companies formed; National Research Foundation formed from FRD. 1999 Sunsat launched (first African-built satellite - Stellenbosch EE Engineering); 2000s South African Space Agency established by national ministry of Science and Technology; SA Navy acquires 4 corvettes which are populated with much local EM industry content; sub-Saharan Westcor project (HVDC electrification scheme from Congo River; many EMI issues). [1] JH Cloete, "A Century of Antenna Engineering and High Frequency Technology in South Africa", 2005 SA IEEE AP/MTT Conference, invited paper, abstracts published only, Technopark, Stellenbosch, Mar 2005. [2] DE Baker, "The Seventies - Setting the Stage for Advanced Antenna Development & EM Research", as [1]. [3] JAG Malherbe, "A personal view of EM", as [1]. [4] BA Austin, "Wireless in the Boer War", 100 Years of Radio, Sept. 1995, IEE Conf. Publ. 411, 1995 pp. 44 - 50. [5] HJ van der Bijl, "Theory and Operating Characteristics of the Thermionic Amplifier", IEEE Classic Paper (reprinted), IEEE Proc., vol. 86, no. 12, Dec 1998, pp. 2455-2467. [6] AC Brown ed., A History of Scientific Endeavour in South Africa, Royal Society of SA, c/o UCT, June 1977. [7] P Brain, SA Radar in WWII, Distrib. by SSS Radar Book Group, PO Box 44553, Claremont 7735, Cape Town, 1993. [8] BA Austin, Schonland: Scientist and Soldier, Witwatersrand University Press, ISBN 1 86814 375 9, 2001. [9] JH Cloete and PW van der Walt, "Antenna and microwave research at Stellenbosch", SA Journal of Science, vol. 84, no. 11, pp. 864-865, Nov/Dec, 1988. [10] AD Broadhurst: history of Natal University EE Eng: http://www.ee.und.ac.za/school/SchoolHistory/HandA.asp