Microwave holographic imaging of intermodulation product sources applied to reflector antennas

Reports on a new form of microwave diagnostic imaging that enables sources of IMP on a reflector antenna to be located. The problem of IMP generation by reflector antennas has been reported by a number of workers including Higa who observed IMP generation due to the metal-oxide-metal (MOM) junctions present on a large aluminium reflector antenna, and Ghione and Orefice who have reported on IMP produced by a carbon fibre reflector. Microwave holographic imaging is now a well established method of antenna diagnostics. By adapting these techniques it is possible to scan a reflector to locate sources of IMP on its surface. Initial obtained by these methods have already been reported, but the authors present further developments including results obtained from a paraboloid reflector.