Design and characterisation model for a linearly polarised patch array fed by serial rectangular waveguide network

A novel method for considering radiating structures independently to their feeding networks is presented. The integration of both parts separately designed suffers a critical misalignment with the theoretical behaviour caused by the mutual coupling effects between adjacent elements. This method analyses radiated near E-field monitors to adjust the whole antenna after joining both independently designed parts. A linearly polarised patch array fed by a rectangular waveguide with internal coupling patches for X band (11-12 GHz) has been designed to validate the method performance. A double stacked microstrip patch structure with an integrated phase compensation microstrip line has been used as radiating element. The coupling patches inside the waveguide are connected to the external radiating patches by means of metallic probes. The presented method requires changes in the feeding structure as in the radiating elements. Several prototypes have been manufactured and measured: the feeding waveguide structure connectorised, the radiating patches connectorised, the union of both with SMA transitions and the final integration into the complete antenna. 18.5 dBi gain and 85% efficiency peak values, as well as 6% usable bandwidth have been experimentally achieved.