Modified conventional turnstile antenna features bifoliate pattern with relatively high gain and good circularity over solid area enclosed by the 0.26 and 1.31 radian angles of elevation. These antennas are intended for high altitude balloon use, their permissible weight is restricted to one pound

Boyer, R. B.

Case, E. W.

Rosa, J.

English

NASA Technical Reports Server

February 1971	 Brief 71-10033 
NASA TECH BRIEF 
Goddard Space Flight Center	
_4V 
NASA Tech Briefs announce new technology derived from the U.S. space program. They are issued to encourage 
commercial application. Tech Briefs are available on a subscription basis from the National Technical Information 
Service, Springfield, Virginia 22151. Requests for individual copies or questions relating to the Tech Brief program may 
be directed to the Technology Utilization Office, NASA, Code KT, Washington, D.C. 20546. 
Wide-Angle, Circularly Polarized, Omnidirectional-Array Antenna 
A unique, ultrahigh frequency, broad-beam, omni-
directional, circularly polarized antenna has been 
designed. The antenna, a modification of the conven-
tional turnstile type, features a bifoliate pattern with
produces a partial null on the axis of the antenna and 
redirects the antenna's maximum gain to elevation 
angles of less than 0.79 rad (45 deg) above the horizon. 
The required pattern shaping is completed by using 
Communications Linkage 
relatively high gain and good circularity over the solid 
area enclosed by the 0.26 and 1.31 rad (15 and 75 deg) 
angles of elevation. 
The high gain and good circularity are achieved 
by pattern shaping using two techniques: The crossed 
elements are spaced nearly one-half wave-length apart 
over a ground plane so that destructive interference
a unique four-element array excited by the horizontal 
dipoles. The array is formed by four vertical elements 
mounted at the ends of these dipoles. 
Because these antennas are intended for high-
altitude weather ballon use, permissible weight is re-
stricted to 0.45 kg (I lb). This weight problem is over-
come by using unique fabrication techniques and 
This document was prepared under the sponsorship of the National	 Governmãnt assumes any liability resulting from the use of the 
Aeronautics and Space Administration. Neither the United States
	 information contained in this document, or warrants that such use 
Government nor any person acting on behalf of the United States	 will be free from privately owned rights.
https://ntrs.nasa.gov/search.jsp?R=19710000033 2020-03-17T02:17:15+00:00Z
lightweight materials. The ground plane is fabricated 
from a lightweight expanded-aluminum mesh 
laminated with an aluminized Mylar film. The com-
posite is then bonded to a tubular aluminum ring. 
The total assembly weighs 0.125 kg (0.276 lb) and has 
a high strength-to-weight ratio. 
The radiating elements and the element support 
structure are made from copper-plated glass-epoxy 
tubing. The total weight of the elements and support 
structure is 0.091 kg (0.201 lb). The electronic 
package four-strand support cord and the six-strand 
stabilizing cords are made of Dacron. Total weight for 
the entire antenna is less than 0.36 kg (0.8 lb). 
Note: 
Requests for further information may be directed to: 
Technology Utilization Officer 
Goddard Space Flight Center 
Code 207.1 
Greenbelt, Maryland 20771 
Reference: TSP7I-10033
Patent status: 
Inquiries about obtaining rights for the commercial 
use of this invention may be made to: 
Patent Counsel 
Mail Code 204 
Goddard Space Flight Center 
Greenbelt, Maryland 20771 
Source: J. Rosa, R. B. Boyer, and

E. W. Case of

Radiation, Inc.

under contract to

Goddard Space Flight Center

(G SC-10928)
. 
Brief 71-10033	 Category 01


Wide-angle, circularly polarized, omnidirectional-array antenna

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