The effect of the number of modes and feed locations in angle-of-arrival estimation using a multimode antenna

Given a multimode antenna and a discrete number of modes, the number of modes used and the farfield patterns of the modes impact the angle-of-arrival (AOA) estimation error. This paper presents an analysis of AOA estimation for a multimode structural radiator for a varying number of modes, where each mode is excited through a different feed location on notional two-dimensional crossed plates. Empirical results for AOA estimation errors versus the number of modes and the location of the feeds for each mode are presented using the maximum likelihood method estimator.