Basic Formulation for Espar Antennas and Reactance Domain Signal Processing

摘要

This paper overviews the theory and techniques on electronically steerable parasitic array radiator (espar) antennas. The antenna concept, features, hardware configuration, and operational principle are explained. A simple mathematical model is proposed with varactor-loaded mutual admittance matrix, equivalent weight vector, effective element length, and equivalent steering vector to characterize the beamforming behavior. The concept of reactance domain signal processing is also proposed to provide the smart functionalities such as high-resolution direction-of-arrival estimation, anti-fading diversity reception, reactive near field measurement, and spatial cross correlation multiple access (SCMA).