Experimental study of a spherical array of circularly polarized elements

The radiation properties of a simple spherical phased array of 16 flat spiral antennas have been investigated experimentally over a frequency range of 0.6 GHz to 3 GHz. The results obtained indicate that such an array is capable of operating with widely spaced antenna elements. The spherical array surface considerably reduces the grating lobe amplitudes in the pattern, thereby making the array broad-band. The polarization characteristics of the radiation field were also studied.