Optimization of the quadrifilar helix antenna

Experimental data on the quadrifilar helix antenna have led to an optimum pitch angle and an optimum ground plane size. The ground plane size is an important parameter, and its optimum diameter is about three times the diameter of the helix. The optimum pitch angle is about35\deg. Beam patterns and ellipticity data are given for the optimized model. Bandwidth is about 4:1.