A receiver discriminating between right and left-hand circularly polarized wireless waves

A brief review of the history of magneto-ionic effects in the ionosphere and the apparatus developed for their investigation is given. Because of the inflexibility of present methods of determining the polarization of received waves, a new scheme has been developed which permits observations to be made over a range of frequencies without readjustment. The principle employed is that of an effectively rotating loop, the rotation being simulated by the modulation in phase quadrature of two loops at right-angles. The theory of operation, the errors and the method of adjustment are investigated. Adjustment can be made with the aid of a test wave of unknown polarization. Some results obtained with the apparatus are discussed, and it is concluded that the two magneto-ionic components are almost circularly polarized, and that the relative intensities are unpredictable unless the complete { P',f } curve appropriate to the time of observation is available. A Fourier-series treatment of the propagation of a pulse of energy of radio frequency in the ionosphere is given in an appendix.