The Application of Circular Arrays to Spacecraft Antenna Problems

This paper is concerned with the problem of obtaining nearly omnidirectional patterns in one plane of large conducting bodies having circular cross sections. To define the problem in terms of discrete sources, calculations were made for typical element patterns F((ϕ') = 1, F(ϕ') = 1 + cos ϕ', and F(ϕ') = 1 + 1/2 cos ϕ'. Array circumferences Zλ from 20λ to 40λ were considered for the number of sources S from S = Z/λ to S = 1.5Z/λ. Several prototype antennas were studied which partially overcome the practical problems of feeding large numbers of discrete sources.