Noise-based antenna terms for active receiving arrays

For active receiving arrays with complex receiver chains, nonreciprocal components in the beamforming network, or digitally sampled and processed output signals, existing transmit-based antenna terms such as gain and radiation efficiency cannot be directly applied. Using the reciprocity principle to obtain an equivalence between the total power radiated by a transmitting antenna and the noise power at the output of a receiving antenna, a new set of more general, receiver-specific antenna terms have been obtained. For passive, reciprocal antennas, the new definitions are rigorously equivalent to existing definitions. The terms have received the IEEE Antenna Definitions Working Group's support for inclusion pending final approval by the Antenna Standards Committee in the next update of the IEEE standard for antenna terms.