Direction-of-Arrival (DoA) estimation is a technique that can be used to improve key parameters of modern wireless systems, including connectivity, coverage and energy efficiency. In its most common implementation, it relies on digital beamforming and requires a number of digital signal processing (DSP) units, which has a negative impact on total system cost and energy consumption [1]. To address these deficiencies, one can use simpler and more energy efficient electronically steerable parasitic array radiator (ESPAR) antenna concept, first proposed in [2], in which a centrally placed active element is surrounded by a number of passive elements that are connected to variable reactances. By setting up the correct values of reactances, one can form a directional main beam, and by changing these values electronically it is possible to rotate the main beam around the antenna.