On the polarization effects of decoupling and matching networks on compact single-polarized antenna arrays for direction finding

We investigate in this paper the effects of Decoupling and Matching Networks (DMNs) to the polarization characteristics of single-polarized microstrip patches used for the Direction of Arrival (DoA) estimation of impinging waves. Additionally, we present results on the Cramer-Rao Lower Bound (CRLB), used as a performance metric, with the aim of evaluating the impact of polarization on the capabilities of the array for direction finding. The effects of DMNs, designed with the goal of decoupling and matching radiating elements, will be analyzed for compact antenna arrays with different inter-element spacings smaller than half of the free-space wavelength.