Statistical analysis and robust design of circularly polarized antennas using sequential approximate optimization

Abstract

In the paper, reliable yield estimation and tolerance-aware design optimization of circular polarization (CP) antennas is discussed. We exploit auxiliary kriging interpolation models established in the vicinity of the nominal design in order to speed up the process of statistical analysis of the antenna structure at hand. Sequential approximate optimization is then applied to carry out robust design of the antenna, here, oriented towards increasing the yield (defined with respect to design specifications imposed on the maximum in-band axial ratio level as well as antenna reflection). Demonstration example of a planar CP antenna with two feed line stubs is provided. Despite a large number of independent geometry parameters, accurate yield estimation is possible at the cost of a hundred EM simulations of the structure, whereas yield improvement (from the initial value of 63.5 percent at the nominal design to 99 percent) is achieved at the cost of 300 EM analyses. Comparison with conventional Monte Carlo analysis is also provided.