Effects of slotline cavity on dual-polarized tapered slot antenna arrays

The tapered slot antenna (TSA) was introduced by Lewis et al. (1974). Its potential of being wideband and widescan makes it a prime candidate for high performance phased arrays. Parameter studies performed on single-polarized TSA arrays indicate that such a high performance array may be possible. Wunsch (see Ph.D dissertation, University of Massachusetrs, Amherst, MA, 1997) presented a full-wave moment method (MoM) analysis program that is capable of analyzing dual-polarized finite TSA arrays. The code has been extended here to include frequency interpolation of the impedance matrix to reduce the computation time to an acceptable level so that a parameter study of dual-polarized TSA arrays can be performed. In this paper, the effects of the slotline cavity portion of the element is shown to have a significant impact on the low-frequency performance of a dual-polarized TSA array and to affect also the mid-band and high-frequency performance.