Compact multi-band direction-finding antenna system
First Claim
1. An antenna system includinga mast, a plurality of antenna arrays colocated on said mast, each said antenna array being separated from each other antenna array by a distance along said mast, and means for shifting a frequency of mast resonance out of the frequency bands of said plurality of antenna arrays.
1 Assignment
0 Petitions
Accused Products
Abstract
An compact and rugged antenna system particularly suited to direction finding includes a plurality of antenna arrays for receiving respective frequency bands and colocated on a mast with separation between antenna arrays along the mast. The mast includes a coil wound of an insulator and functioning as a loaded inductor to shift the mast resonance out of the frequency band of the antenna system. A VHF dipole array having elements shaped to reduce scattering to UHF and SHF arrays is supported on movable arms which allow retraction that reduces height and provides mechanical protection to one or more other arrays as well as damping against vibration by contacting the mast with shaped portions of the dipole elements. The bowtie elements of the UHF array are angled at a central region to optimize array diameter at low UHF frequencies. A finned RF electronics housing is preferably provided which reduces solar loading and dissipates heat from antenna electronics. Asymmetrically keyed fittings are provided to permit accurate antenna system, array and element positioning and replaceable components and wiring, both internally and externally of the housing, is held in position to allow field repairs without recalibration.
-
Citations
27 Claims
-
1. An antenna system including
a mast, a plurality of antenna arrays colocated on said mast, each said antenna array being separated from each other antenna array by a distance along said mast, and means for shifting a frequency of mast resonance out of the frequency bands of said plurality of antenna arrays.
Specification