Abstract: The talk will be centred on a recent discovery that electromagnetic waves are generated not only due to acceleration of electrons as proposed by Maxwell, but also as a result of symmetry breaking of the electric field in space associated with electron acceleration. This offers a unified approach towards understanding the mechanism of radiation from diverse kind of antennas- dielectric, piezoelectric, metallic wire or a simple inductor-capacitor antenna. The concept of radiation under explicit symmetry breaking will be used to explain some of the difficult and open ended problems in antenna physics, most notably, the working of dielectric antennas whose operational mechanism remained unclear until now. A new perspective regarding design of antennas while using existing circuit components like capacitors in conjunction with other metallic components which form part of the ground plane of an electronic device will be presented while highlighting the fact that it may lead to integration of antennas on an electronic chip, one of the biggest challenges of semiconductor industry.
In explicit symmetry breaking, the system's symmetry is explicitly broken by a careful design of the system such that the dynamic equations are not invariant. For example, a two wire parallel transmission line system does not result in radio wave emission despite electron acceleration as the electric field lines have symmetry i.e. invariance along the spatial direction between the transmission lines. But when the wires are flared or opened up, there is a change in the shape of electric field lines, i.e. symmetry is explicitly broken resulting in radiation with an associated non-conserved current which is emitted out from the system.
Bio: Prof. Gehan Amaratunga FREng., FIET, CEng. obtained his B.Sc ('79) from Cardiff University and Ph.D ('83) from Cambridge, both in electrical/electronic engineering. He has held the 1966 Professorship in Engineering at the University of Cambridge since 1998. He currently heads the Electronics, Power and Energy Conversion Group, one of four major research groups within the Electrical Engineering Division of the Cambridge Engineering Faculty. Professor Amaratunga’s research is in the broad area of materials and technologies for electrical energy and power. It intersects electrical and electronic engineering with chemistry, physics, materials science and information systems. He has an active research programme on the synthesis and electronic applications of carbon nanotubes and other nanoscale materials. His group has many 'firsts' emanating from his research in carbon, including field emission from N doped thin film amorphous carbon and diamond, laboratory synthesis of carbon nanonions, tetrahedral amorphous carbon ('amorphous diamond')-Si heterojunctions , deterministic growth of single isolated carbon nanotubes in devices, high current nanotube field emitters and the polymer-nanotube composite solar cells. His group was amongst the first to demonstrate integration of logic level electronics for signal processing and high voltage power transistors in a single IC (chip). His current research is focussed on integrated power conversion circuits. Professor Amaratunga is a founder of five technology start-up companies: CamSemi and Enecsys in the area of electronics which have attracted in excess of $120M in venture capital funding and have class leading commercial products in the market, Nanoinstruments in the area of nanotechnology which was acquired by Aixtron AG in 2007 and WindTechnologies and Camutronics which are at earlier stages of product development. He has previously held faculty positions at the Universities of Liverpool (Chair in Electrical Engineering), Cambridge, and Southampton. He has held the UK Royal Academy of Engineering Overseas Research Award at Stanford University and been a Royal Society visitor at the School of Physics, University of Sydney. Professor Amaratunga was elected a Fellow of the Royal Academy of Engineering in 2004. In 2007 he was awarded the Royal Academy of Engineering Silver Medal 'for outstanding personal contributions to British engineering'. He has published over 500 archived journal and conference papers (~15000 citations) and is an inventor on 32 patents.