A detailed experimental study of the factors influencing the polar diagram of a dipole in a parabolic mirror

Experimental work is described on the behaviour of a coaxial-fed dipole aerial in a parabolic mirror. Measurements of beam position relative to the mirror to an accuracy of the order of one minute of arc are given for variations in the geometry of the system. It is shown that large changes of direction can occur. Results are also quoted for a dipole designed to give a ¿skewed¿ beam without mechanical displacement.