Techniques for Handling Elliptically Polarized Waves with Special Reference to Antennas: Introduction

Abstract

Methods are described for representing the elliptical polarization of waves in forms especially convenient for use with elliptically polarized transmitting and receiving antennas. In Part I of this paper V. H. Rumsey shows how an ordinary impedance chart (Carter or Smith) may be used for representation of elliptical polarization. The description of elliptical polarization involves a statement about the relative amplitudes and phases of a pair of vibrating quantities, and this is also what is involved in impedance. Consequently, the whole apparatus of impedance may be neatly adapted for representation of elliptical polarization. In Part II G. A. Deschamps recalls and applies a method of H. Poincaré for representing elliptically polarized light waves. Latitude and longitude on a sphere are used to represent the shape and orientation of the ellipse. A suitable map-projection of the Poincaré sphere then leads to the representation of elliptical polarization on an impedance chart described in Part I. It has already been shown by G. Sinclair that the usual concept of "equivalent length" becomes complex for an elliptically polarized antenna, and in Part II of this paper Deschamps shows how to introduce a real equivalent length for such antennas. In Part III M. L. Kales presents a rather comprehensive theory of elliptical polarization in terms of a three-dimensional vector each of whose components is a phasor. The algebra of such complex vectors facilitates the mathematical handling of elliptical polarization. In Part IV J.I. Bohnert described measuring techniques for elliptically polarized antennas.