Relationships between antennas as scatterers and as radiators

Abstract

The field scattered by an antenna contains a component that is the short circuit scattered field normalized by the short circuit current and a second component that is the radiation field normalized by the transmitting current and multiplied by a factor (1- Gamma ). The RCS is the magnitude squared of the difference between two terms, one being the square root of a complex 'structural' cross section, and the other (1- Gamma ) times the square root of a complex 'antenna' cross section. These relationships, and the role of the load impedance are clarified. The connection between antenna directivity and load effective receiving area is also derived.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>