Reduction of mutual coupling between active monopoles: Application to superdirective receiving arrays

Theoretical results and measurements of mutual coupling between active monopoles show that the incorporation of a field-effect transistor (FET) with a shunt input inductance leads to large reduction of interactions at reception. Each active monopole then works as an isolated element, and feed requirements of active array become easier to obtain. Realization of a superdirective array with an appreciable bandwidth confirms the main possibilities of active antennas.