Low cross-polarisation high-isolation frequency scanning aperture coupled microstrip patch antenna array with matched dual-polarisation radiation patterns

A method of beam matching between two linear polarised radiation patterns of a dual-polarised frequency scanning antenna is proposed, implemented, and tested. A meticulous phase match process between the outputs of both individual cells and the whole corresponding horizontal and vertical feed lines is carried out. To verify the simulation results and to take the coupling effect into account, the radiation patterns of an isolated column, as well as those of three columns, are measured. In agreement with the design and with the simulation results, horizontal and vertical polarisation beams with a pointing angle mismatch of less than +/- 0.2 degrees within the resonant frequency bandwidth of 2.75-2.95 GHz are achieved.