
Accession Number : AD0265852
Title : A SOLUTION TO THE FREQUENCYINDEPENDENT ANTENNA PROBLEM
Corporate Author : CALIFORNIA UNIV BERKELEY ELECTRONICS RESEARCH LAB
Personal Author(s) : CHEO,B. ; RUMSEY,V.H. ; WELCH,W.J.
Report Date : 14 JUN 1961
Pagination or Media Count : 1
Abstract : A solution of Maxwell's equations is obtained for an antenna consisting of an infinite number of equally spaced wires in the form of coplanar equiangular spirals. Radiation amplitude patterns obtained from this solution agree closely with measurements on twoelement spiral antennas. The phase pattern shows the approximate validity of a phase center at a distance behind the antenna which decreases with the tightness of the spiral. The current distribution clearly shows increased attenuation with increase in the tightness of the spiral thus showing how the frequencyindependent mode depends on the curvature. A remarkable feature of the solution is that the current consists of an inward traveling wave at infinity when the antenna is excited in that sense which produces an outward wave at the center. (Author)
Descriptors : *HELICAL ANTENNAS, AMPLIFIERS, ANTENNA RADIATION PATTERNS, ANTENNAS, ATTENUATION, ELECTROMAGNETIC PROPERTIES, EXCITATION, FREQUENCY SHIFT, PARTIAL DIFFERENTIAL EQUATIONS, WAVE PROPAGATION
Distribution Statement : APPROVED FOR PUBLIC RELEASE