A New Method for Gain Prediction of Superdirective End-Fire Arrays

Overview & Synopsis

The problem of gain estimation of a superdirective dipole-based array is discussed. The current method to compute the gain, for a given element radiation efficiency, is based on the Array Factor (AF) Theory. In this work it is intended to show that an equivalent formulation can be done using the Spherical Wave Expansion (SWE) theory. Besides the interest in validating this theory, the main objective is a better understanding of the radiation and attenuation phenomena that occurs in superdirective arrays. Moreover, the numerical sensitivity affecting the problem diverges as the inter-elements distance tends to zero. Having a larger set of functions describing the radiated field, such as in the case of the SWE theory, allows the possibility to decrease the sensitivity. Consequentially the sensitivity limits imposed by the classical formulation in AF theory can be overcame