Characteristics of 5 to 35 turn uniform helical antennas
Abstract
The measured VSWR, gain, pattern and axial ratio characteristics of a uniformly wound helical antenna are presented. Experimental parametric studies were made of (1) fixed length helices with variable diameter and pitch angle (8.6 to 10 turns), and (2) variable length helices with constant diameter and pitch angle (5 to 35 turns). Simplified design relations are given for the antenna gain and halfpower beamwidth (HPBW) as a function of axial length L/lambda and circumference C/lambda for helices consisting of approximately 10 turns. Parametric curves are presented to show the gain and HPBW of a constant pitch helix as a function of L/lambda and C/lambda. An empirical expression is derived for the antenna gain as a function of frequency and the helix design parameters. In addition, the bandwidth characteristics are analyzed.
 Publication:

Final Report Aerospace Corp
 Pub Date:
 June 1977
 Bibcode:
 1977aero.rept.....K
 Keywords:

 Antenna Radiation Patterns;
 Helical Antennas;
 Standing Wave Ratios;
 Variable Pitch Propellers;
 Bandwidth;
 Cavity Resonators;
 Pitch (Inclination);
 Communications and Radar