Application of microwave absorbers in multilayer antenna arrays

Some practical problems concerning the application of microwave absorbers in multilayer antenna arrays are discussed. Several examples are described for illustration of the suppression of parasitic influences and excitations in the antenna feeds: resonance attenuation and phase delay in meandered microstrip lines; parallel-plate modes in stripline feeds, resonance coupling between different layers etc. The utilization of absorbing microwave coating for realization of simple attenuators/phase shifters, as well as planar loads for distributing components in antenna feeds are additionally considered.