Radiation Pattern of Large Planar Arrays Using Four Small Subarrays

The active element pattern (AEP) method is usually employed to efficiently predict the radiation from large arrays when the direct analysis methods are infeasible. However, the standard AEP method needs to compute and store the AEP of each subarray element, and then the AEPs are used to construct those of the large array. To eliminate this cumbersome process, a simplified AEP method is proposed, which only uses the total radiation field of four small subarrays to construct the radiation pattern of large planar arrays. Theoretical derivation of the proposed method is presented. This method has the same accuracy as the standard AEP method, and it is only effective for broadside and uniform excitation arrays. Example arrays of microstrip patch antennas are analyzed and the calculated patterns agree well with those simulated by HFSS.