Wideband microstrip dual polarization radiator for X-band APAA

In this paper the model and the construction of a wideband microstrip X-band radiator of active phased antenna arrays have been presented. The basic demands to the radiator have been formulated. The results of computer electromagnetic simulation of the radiator in free space and in the infinite array have been given, as well as the results of radiator experimental testing in the waveguide simulator. The characteristics of a proposed radiator such as VSWR, decoupling coefficient and losses have been simulated and estimated experimentally on the test sample. Experiment has shown good agreement with numerical simulation results. Particularly, 20% bandwidth with VSWR no greater than 2 has been achieved. Sample testing in a waveguide simulator gives 0,5 dB loss (active and return loss in radiator without loss in simulator itself). Scan angle at 3 dB gain loss, as it follows from numerical simulation results, should be no less than ±40° or ±45° in the main planes. So, proposed microstrip radiator may be used for X-band active phased arrays, which should work in 20% bandwidth with steerable polarization.