Abstract: Steerable antenna on platforms, fixed or mobile, are tracked to form an RF communication link by setting the width of the main lobe of the antenna beam pattern to be greater than the initial pointing uncertainty region and then concurrently scanning and progressively reducing the widths of the main lobes as the pointing uncertainty region is reduced to first acquire and then track the opposing antenna. The width of the main lobe is reduced such that the width of the main lobe is approximately fixed for each block. The antennas at opposite ends of the communication link may be scanned with scan patterns that are orthogonal to each other such that the demodulation of the received signal levels to signal direction of arrival at each platform is solely a function of the scan pattern of the receive antenna.

Abstract: Steerable antenna on platforms, fixed or mobile, are tracked to form an RF communication link by setting the width of the main lobe of the antenna beam pattern to be greater than the initial pointing uncertainty region and then concurrently scanning and progressively reducing the widths of the main lobes as the pointing uncertainty region is reduced to first acquire and then track the opposing antenna. The width of the main lobe is reduced such that the width of the main lobe is approximately fixed for each block. The antennas at opposite ends of the communication link may be scanned with scan patterns that are orthogonal to each other such that the demodulation of the received signal levels to signal direction of arrival at each platform is solely a function of the scan pattern of the receive antenna.

Abstract: An antenna array system includes a plurality of antenna array elements and an array controller in communication with each of the array elements. Each array element further includes an antenna, a computing device, and a storage device maintaining a position vector uniquely identifying the position of its antenna within the array. The array controller broadcasts, to each array element, a signal including a direction vector representative of a desired beam steering direction. Employing their respective computing devices, each array element calculates its phase based upon stored position vector and the received direction vector. The antenna of each array element further emits an electromagnetic wave based upon its calculated phase. The net electromagnetic wave resulting from combination of the respective emissions of the antenna array elements is aligned with the desired beam steering direction.

Abstract: A system for tracking a target includes a dual-band antenna. The dual-band antenna includes a first antenna and a second antenna rigidly coupled to the first antenna. The first antenna is configured to communicate within a first frequency band and the second antenna is configured to communicate within a second frequency band. The system further includes a processing system having a first antenna control processor configured to initialize a pointing direction to point a beam of the first antenna toward the target with a first degree of pointing accuracy, and configured to scan with the first antenna to point the beam of the first antenna more precisely toward the target with a second degree of pointing accuracy, and further having a second antenna control processor configured to electronically scan with the second antenna to point a beam of the second antenna to the target with a third degree of pointing accuracy.

Abstract: A method and an apparatus for generating an error estimate as input for an error recovery loop of a demodulator which receives an offset quadrature phase shift keyed (OQPSK) signal having a symbol interval. The method comprises the following operations: (a) receiving at least four consecutive complex samples z.sub.-1/2, z.sub.0, z.sub.1/2 and z.sub.1 obtained by sampling the OQPSK signal at half the symbol interval; and (b) computing the error estimate based on the complex samples z.sub.-.sub.1/2, z.sub.0, z.sub.1/2 and z.sub.1.