GB969660A - Antenna structures - Google Patents

Abstract

969,660. Aerials. GRANGER ASSOCIATES. Jan. 23, 1962 [Jan. 27, 1961], No. 2489/62. Heading H4A. An aerial comprises at least three mutually spaced folded radiators of like shape arranged in a plane, the dimensions of the radiators and their spacing increasing uniformly and proportionally with increase in their distance from a vertex and a feeder coupled to corresponding points of the radiators. In one embodiment, Figs. 3a, Fig. 3e, X n = #X n - 1 X n + 1 and R n = #R n - 1 R n + 1 a reflector 3 is provided and a matching capacitor 15 formed by a U-shaped wire having insulated legs 21 is included adjacent to the apex of the aerial, Fig. 3b (not shown). Feeder 10, 11 is coupled to the " further " sides 9<SP>1</SP> of " folded dipoles " 7 by capacitance introduced by insulating sleeves 11. The equivalent unipole array with counterpoise 14 is illustrated by Fig. 5b. It is stated that the voltage standing wave ratio is less than 3: 1 over a 3:1 frequency range, Fig. 7 (not shown). The disclosure of the invention is preceded by a discussion of known " log-periodic " aerials.