A space-fed local oscillator for spaceborne phased arrays

A space-fed local oscillator concept for deployable spaceborne phased arrays is described that uses a local oscillator radiator on the back side of the array along with a series of local oscillator pickup elements connected to the array elements. This concept provides partial compensation for the dynamic deformations that occur on-orbit when lightweight deployable array designs are used. An analysis of the array pattern gives results that differ from those predicted on the basis of the random phase perturbations used in classic antenna tolerance theory. The concept also provides effective compensation for peak array deformations that are as large as 0.3 wavelengths. The compensated patterns are comparable to those achieved by conventional local oscillator distribution techniques with about 0.1 wavelength peak mode distortion. Thus, the structural requirements for the array are reduced by the space-fed local oscillator compensation with the potential benefit of weight reduction.<>