Evanescent spherical waves of scalar point source

It is well known that evanescent waves decay exponentially from a wave source and influence on a near field of the particular source. In a zero frequency limit these waves decay according to a power law around a spherical source. In the paper exact calculations of an evanescent and homogeneous field in the zero frequency limit has been performed. The calculations base on an angular spectrum representation of a spherical wave using Weyl's expansion technique. (C) 2016 Elsevier GmbH. All rights reserved.