Expedited amplitude and phase tolerance analysis of reflector antenna systems with vector spherical waves

Abstract

This work presents the relevant advantages of analyzing a complete reflector antenna system based on: 1) the expansion of the feed radiated field in terms of vector spherical waves (VSWs) and 2) the characterization of the reflector domain with VSWs. It requires that the reflector be initially analyzed under the illumination of each single VSW. The output of each of these analyses is the radiated field of the reflector for each VSW excitation. Then, the accurate response of the complete antenna system, both in amplitude and phase, can be directly obtained by just linear combination of these individual-VSW-excited radiated fields, weighted by the feed transmission vector that relates the coefficients of the VSW expansions for the feeder with its input excitation mode. Thanks to the orthogonality of the VSWs, and the applicability of the far-field approximation, it turns into a very efficient approach for the whole end-to-end analysis, adding useful capabilities and flexibility for the expedited assessment of tolerances.