Abstract: A directionally-tunable antenna element of an antenna is provided. The directionally-tunable antenna element includes a feed structure, a coupling structure, and a ridge structure. The coupling structure is disposed between the feed structure and the ridge structure and communicates electromagnetic energy between the feed structure and the ridge structure. These structures address challenges associated with satellite tracking and frequent satellite handoffs in an electronically scanned array (ESA). The disclosed aspects enhance performance of ESA antenna systems, addressing shortcomings of ESA antenna systems yet while addressing the satellite tracking and frequent satellite handoff challenges. The disclosed aspects provide for antennas with highly efficient useable gain bandwidth, high scan angle performance, and consistent and high cross polar isolation over a full scan angle range.

Abstract: An antenna element includes a balun configured to convert an unbalanced signal to a balanced signal and having an input, a first output, and a second output. The antenna element further includes a feed layer having a first feed coupled to the first output of the balun, a second feed coupled to the second output of the balun, a first ridge coupled to the first feed, a second ridge coupled to the second feed, and a center post.

Abstract: An antenna element includes a balun configured to convert an unbalanced signal to a balanced signal and having an input, a first output, and a second output. The antenna element further includes a feed layer having a first feed coupled to the first output of the balun, a second feed coupled to the second output of the balun, a first ridge coupled to the first feed, a second ridge coupled to the second feed, and a center post.

Abstract: An electronic scanning radio direction finding system for accurate direction finding of radio frequency signals using singly or doubly flared cylindrical reflectors surrounded by a circular array of inwardly facing feed horns. The array is operated as a phased array to determine the direction of origin of received signals. The feed horns can also be used to transmit RF signals on very narrowly controlled beams with minimal side lobes. The flared cylindrical reflector and its circular feed horn array may be paired with circular log periodic arrays operable at similar frequency ranges or different frequency ranges to provide more precise direction finding and direction finding of signals at frequencies beyond the range of the flared cylindrical reflector and its circular feed horn array.

Abstract: An electronic scanning radio direction finding system for accurate direction finding of radio frequency signals using singly or doubly flared cylindrical reflectors surrounded by a circular array of inwardly facing feed horns. The array is operated as a phased array to determine the direction of origin of received signals. The feed horns can also be used to transmit RF signals on very narrowly controlled beams with minimal side lobes. The flared cylindrical reflector and its circular feed horn array may be paired with circular log periodic arrays operable at similar frequency ranges or different frequency ranges to provide more precise direction finding and direction finding of signals at frequencies beyond the range of the flared cylindrical reflector and its circular feed horn array.

Abstract: An electronic scanning radio direction finding system for accurate direction finding of radio frequency signals using singly or doubly flared cylindrical reflectors surrounded by a circular array of inwardly facing feed horns. The array is operated as a phased array to determine the direction of origin of received signals. The feed horns can also be used to transmit RF signals on very narrowly controlled beams with minimal side lobes. The flared cylindrical reflector and its circular feed horn array may be paired with circular log periodic arrays operable at similar frequency ranges or different frequency ranges to provide more precise direction finding and direction finding of signals at frequencies beyond the range of the flared cylindrical reflector and its circular feed horn array.