The performance of an iris-loaded planar phased-array antenna of rectangular waveguides with an external dielectric sheet

• Published in: I.R.E. transactions on antennas and propagation 1978-05, Vol.26 (3), p.413-419
• Main Author: van Schaik, H.
• Format: Article
• Language: English
• Subjects: Antenna measurements; Aperture antennas; Dielectrics; Loaded antennas; Permittivity; Planar arrays; Planar waveguides; Rectangular waveguides; Transmitting antennas; Waveguide discontinuities
• ISSN: 0018-926X; 0096-1973; 1558-2221
• DOI: 10.1109/TAP.1978.1141860

A new method for calculating the performance of an iris-loaded planar phased-array antenna of rectangular waveguides is presented. The method is based upon the expansion of the tangential electric aperture field in terms of judiciously chosen functions. Also, the influence of a dielectric sheet in front of an antenna the apertures of which are loaded with inductive irises is investigated. In the experiments, a sheet with a low relative permittivity ( \epsilon_{r} = 2.3 or \epsilon_{r} = 3.5 ) is spaced in front of a space-fed planar antenna of some 850 radiating elements, and the total transmitted power of the antenna is measured as a function of frequency and scan angle. The results indicate, that both in theory and in practice, an excellent match can be achieved with a polythene sheet ( \epsilon_{r} = 2.3 ) or a Perspex sheet ( \epsilon_{r} = 3.5 ).