Waveguide-sandwich electromagnetic window

The reflection and transmission properties of a new symmetrical radome-wall construction are obtained from a matrix representation. The structure consists of a sandwich of two layers of dielectric material enclosing a medium of artificial dielectric in the form of a 2-dimensional array of waveguides, as is used in waveguide lenses. Two important properties are disclosed: first, the possibility of creating a reflectionless radome with no insertion phase delay (i.p.d.), and, secondly, thin radomes with bandwidths of 10:1 for a power-reflection loss less than 10%, despite the cutoff effect of the centre medium.