Title :
Transmitting, receiving, and scattering properties of antennas
Author :
Andersen, Jorgen Bach ; Vaughan, Rodney G.
Author_Institution :
Center for Personkommunikation, Aalborg Univ., Denmark
Abstract :
In most modern textbooks on antennas, it is stated that receiving antennas scatter as much as they absorb under matched-load conditions. This is incorrect, as was shown 50 years ago. The reason for this discrepancy is an apparently incorrect use of the equivalent circuits. In this tutorial paper, a simple example of a two-element Yagi antenna and a test dipole in the far field is analyzed for transmission, reception, and scattering, through the use of the symmetric impedance matrix. It is shown that the correct equivalent circuit for the scattering case is more complicated, owing to the existence of more sources than in the transmitting case. Through a numerical example, it is also shown that the scattered power may be larger, equal to, or smaller than the absorbed power.
Keywords :
Yagi antenna arrays; antenna radiation patterns; dipole antennas; electromagnetic wave absorption; electromagnetic wave scattering; equivalent circuits; impedance matching; impedance matrix; receiving antennas; transmitting antennas; absorbed power; equivalent circuits; far field; matched-load conditions; receiving antennas; scattered power; scattering properties; symmetric impedance matrix; test dipole; transmitting antennas; two-element Yagi antenna; Aperture antennas; Circuit testing; Dipole antennas; Electromagnetic scattering; Equivalent circuits; Impedance; Loaded antennas; Receiving antennas; Transmitting antennas; Yagi-Uda antennas;
Journal_Title :
Antennas and Propagation Magazine, IEEE
DOI :
10.1109/MAP.2003.1241316