Conical beam, horizontally polarised antennas for HIPERLAN

It is shown that a conical beam 5.2 GHz antenna suitable for HIPERLAN application, but working in horizontal polarisation, can be realised as a group of microstrip patch radiators in a ring formation. Layouts with three and four patches are described, and radiation patterns are found to agree well with predictions from a simple array model. The three patch form is smaller and gives a closer approximation to an azimuth independent pattern. Patterns are very similar to those achieved in vertical polarisation with reported disc antenna realisations, giving peak radiation at about 50/spl deg/ elevation. Two methods of impedance matching are found to give satisfactory results.