AN INVESTIGATION OF THE EXTENT OF THE FRESNEL REGION OF APERTURE ANTENNAS WITH ATTENTION TO SUPERDIRECTIVITY

Authors
  1. Charland, S.
Corporate Authors
Defence Research Establishment Ottawa, Ottawa ONT (CAN)
Abstract
The technical note describes the principles governing superdirective antennas and the factors limiting their realization. A criterion for determining the minimum distance to the far field of aperture antennas, including superdirective antennas, is presented. Under this condition it is shown that, at least for the marginally superdirective case, such antennas do not exhibit large fresnel regions as compared with uniformly phased apertures. A modified criterion is also presented which defines the minimum distance to the far field in a given direction. Under this criterion it is shown that for the uniform distribution, the antenna pattern near nulls requires a large distance to converge to the far field form. This work has applications in determining antenna test range requirements.
Report Number
DREO-TN-89-20 — Technical Note
Date of publication
15 Aug 1989
Number of Pages
99
DSTKIM No
90-00952
CANDIS No
63226
Format(s):
Hardcopy;Originator's fiche received by DSIS

Permanent link

Document 1 of 1

Date modified: