Polytechnic Institute of Brooklyn

  • Herbert Kurass

Abstract

Antennas with identical patterns differ to the extent in which they n~odify an incident wave, i.e., in the amount they scatter. An antenna is completely described by an (infinite dimensional) scattering matrix. The concept of a minimum scattering antenna introduced by Dicke is generalized to include antennas with a finite number of accessible waveguide ports and with non-reciprocal componants. A canoniral minimum scattering antenna is defined as on, which becomes "invisible' when the accessible waveguide term-nal.: arc. open circuited. Such an antenna is shown to be unique once the independent radiation patterns have been specified. Neither an impedance nor an --dm.ttaLce matrix for such an antenna exists. The physical significance of the' :n-iinurn scrttt-rirg antenna concept is examined from several points of view. Approirite eaecralizations of Dicke' a results are derived for mu3ktiport ari no--rezip:oczai antennas. The "scattered power 0, is introduced as a convenient measure of &c4Attering. It is demonstrated, for a large class of antennas, t•a the scaterced power is quite generally greater than the absorbed power, equality being attained for minimum scattering antennas cG this class. This result further justifies the mv4 'niiur-scat.ering terminology. Arrays of canonical antennas are discussed briefly. The work reported hereia was sponsored by the Air Force Office of Scientific Research of the Office of Aerospace Research: the department of the Arrry, Army Research Office; and the department of the Navy, Office of Naval Research up'jer Grant AF-AFOSR-453-63, and by the National Science Vo,uviation under Grant GP-Z761. MINIMUM-SCATTERING ANTENNAS

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Cite this paper

@inproceedings{KurassPolytechnicIO, title={Polytechnic Institute of Brooklyn}, author={Herbert Kurass} }