Prospects for varactor scanning microstrip arrays

Research today is directed towards the evolution of highly sophisticated phased arrays but there is also considerable interest in the development of simpler techniques offering limited beam scanning facilities but possibly lower costs along with other advantages. A novel approach is described which relies on the varactor diode control of the element excitation in a microstrip antenna. A microstrip line is designed to serve the dual role of phase shifter and feeder for microstrip arrays using the travelling-wave array principal. Recent results are summarised and the prospects of applying this new technique at higher microwave frequencies and millimetre bands, possibly using integrated antennas, is considered