Optimized Antennas for Multispectrum Guidance

Modern seeker systems that employ multispectrum technology to optimize missile guidance performance are limited by the available volume. Specifically, placement of an IR seeker in the nose of an RF seeker radome creates blockage effects that vary as a function of the angle of the gimballed RF seeker. The resulting imbalances in the antenna aperture and associated losses can degrade tracking performance. It is desired to optimize the average tracking performance over all seeker/target aspect angles, or preferably, to optimize performance at each required operational aspect angle. The proposal detailed herein describes the use of digital beamforming (DBF) arrays as a means to allow the aperture illumination to be optimized at each aspect angle in the presence of symmetrical or asymmetrical blockage such as presented by an IR seeker. The DBF concept also allows for individual optimization of the sum and difference pattern weights of a monopulse tracking seeker. In addition, calibration techniques allow for the relaxation of RF component performance requirements.