Two-Port Representation of an Antenna With Application to Non-Foster Matching Networks

A new theoretical tool is introduced for treating an antenna as a two-port network. This tool is very useful for allowing the antenna and its matching network to be analyzed and optimized in a circuit simulator. In this paper, we apply the idea to the situation where the matching network of the antenna incorporates non-Foster (active) matching elements, and so overall circuit stability becomes an overriding consideration. Non-Foster matching networks are particularly interesting because they offer the potential to transform the antenna into an active component that is no longer limited by the gain-bandwidth-size constraints of passive antennas, and whose performance can be improved as semiconductor technology advances.