The receiving and scattering properties of antenna elements and finite arrays

An interesting and somewhat controversial topic is the receiving and scattering properties of the general antenna. In recent years, this topic has been given considerable attention in the IEEE AP-S Magazine. In this presentation, we consider the fundamental receiving and scattering properties of antenna elements and finite arrays. We examine the general validity and application of the Thevenin and Norton equivalent circuits to resonant and antiresonant antennas in terms of predicting both received and scattered powers. We consider the concept of scattered power in view of it being non-recoverable and in terms of its relation to the received power and the law of conservation of power. We consider the receiving and scattering properties of electrically small antennas as well as finite arrays and the concept of whether a finite array absorbs or receives all available power. Circuit theory and numerical simulations of the receiving and scattering properties of both single elements and finite arrays are used as examples. We demonstrate that the law of conservation of power necessitates the fact that any antenna or array that receives power must also scatter power.