Abstract: A circular polarized signal receiving antenna includes an active element having first and second ends separated by a gap. A dimension of the active element between the first and second ends thereof corresponds to approximately one wavelength of a resonant operating frequency of the antenna. A feed-point is coupled to the active element, wherein the feed-point is located approximately one-quarter of the wavelength from the first end of the active element and approximately three-quarters of the wavelength from the second end of the active element. In one embodiment, the feed-point is coupled to the active element.

Abstract: A circular polarized signal receiving antenna including an active element having first and second ends separated by a gap, a dimension of the active element, between the first and second ends thereof, corresponding to approximately one wavelength of a resonant operating frequency of the antenna. A feed-point is coupled to the active element, wherein the feed-point is located approximately one-quarter of the wavelength from the first end of the active element and approximately three-quarters of the wavelength from the second end of the active element. In one embodiment, the feed-point is coupled to the active element.

Abstract: A circular polarized signal receiving antenna (100) including an active element having first and second ends separated by a gap, a dimension of the active element, between the first and second ends thereof, corresponding to approximately one wavelength of a resonant operating frequency of the antenna. A feed-point is coupled to the active element, wherein the feed-point is located approximately one-quarter of the wavelength from the first end of the active element and approximately three-quarters of the wavelength from the second end of the active element. In one embodiment, the feed-point is reactively coupled to the active element.

Abstract: An interferometer type DF system uses an array of five antennas (A,B,C,D,E) arranged at the apices of a regular pentagon to define five wide apertures along the sides of the pentagon and a further five apertures along the diagonals. The phases of the signals received by each antenna, are measured modulo 2.pi. and processed to give a unique bearing of the radio source to the accuracy of the widest aperture defined by the array. One method of processing the phases is to calculate from them the Fourier coefficients of the Fourier series representing the spatial phase distribution. By comparing the difference between each calculated coefficient and a corresponding order coefficient of a set of imaginary antenna phases expressed as integral multiples of 2.pi., the complete 2.pi. phase differences between the measured phases modulo 2.pi. can be found.