Professor John David Rhodes is best known for his analysis and design of microwave components and filters. David’s major contributions to this branch of electronics has not been confined to academic aspects of the topic. It encompasses new theory for filters and multiplexers, the practical implementation of their design in waveguide and microstrip form and the engineering development of such components — including new techniques for their industrial manufacture. He has made major contributions to circuit analysis and synthesis and was the first to synthesise the effective and hence very efficient class of microwave elliptic filters. The contributions also include the development of specialised software packages needed for computer-aided design of systems involving high mechanical tolerances required for operations at frequencies up to 100 gigahertz. Whilst still holding a chair at the University of Leeds, David formed his own company which now takes a leading role in the manufacture of multiplexers and filters to an international market. Such devices are now extensively used in communication satellites and military systems He has received the OBE (the Officer of the Order of the British Empire) and CBE (the Commander of the Order of the British Empire) from the Queen and also several Technology and Export Awards. From the University of Leeds he received the BSc. Ph.D., D.Sc. and Honorary D.Eng Degrees and further Honorary Degrees from Bradford and Napier Universities. He is a fellow of the IEEE, IET, Royal Academy of Engineering, The Royal Society and a Foreign Associate of the Academy of Engineering (USA). He has been awarded numerous prizes including the Microwave Prize, the Browder J. Thompson Award, The Guillemin-Cauer Award and the Microwave Career Award all from the IEEE; The JJ Thomson Medal and the Faraday Medal from the IET; The Mountbatten Medal from the National Electronics Council; The Mullard Award from the Royal Society, and the premier distinction from the Royal Academy of Engineering, The Prince Philip Gold Medal. Many years ago he founded Filtronic plc and grew it into an international microwave company with 10 operations on 4 continents with peak sales of $0.5 B and a market capitalisation of $2.5 B. He retired 4 years ago and has grown a new business within the private company Isotek Electronics Ltd., where he is the majority shareholder, in the area of microwave sub-systems. Isotek Electronics Ltd. is currently being acquired by Filtronic plc. The remaining Isotek business, which develops and manufactures hyperbaric welding systems for sea depths down to 4000 m, continues to grow under his ownership. He is also an Emeritus Professor at the University of Leeds.