Dipole arrays printed on ferrite substrates

The authors report on the radiation from infinite dipole arrays printed on ferrite substrates. Ferrite materials offer unique design capabilities at microwave frequencies because some of their properties depend on the DC magnetic field applied to them. The performance of an array of printed elements depends strongly on, among other things, the modes supported by the substrate. The nature of grounded ferrite substrate modes and their relation to the scan performance of dipole arrays printed on such ferrite substrates are described. Both in-plane and perpendicular bias are considered, and a scheme of dynamic ferrite biasing is outlined resulting in unique scan performance and a 16% frequency agility of ferrite substrate dipole arrays