A Simple Measurement Technique for Accurate Bistatic Retrodirective Radiation Pattern Calculation Based on the Active Element Pattern Method

This communication presents a new method for calculating bistatic responses from retrodirective arrays when only monostatic measurement data are available. The proposed approach offers considerable simplification to the measurement facilities required for retrodirective array characterization, since bistatic measurements are significantly more complicated to perform in comparison with monostatic measurements. The method involves making some minor changes to the monostatic measurement configuration, enabling the capture of active element patterns with magnitude and phase data, and combining these with a new expression to obtain the bistatic calculation. Very close agreement has been obtained when compared to actual measured bistatic responses of a ten element retrodirective patch array. In particular, the predicted beam position from the new method is within 0.25° at 40° scan angle, compared to a disagreement of 1.5° using previously reported methods.