Accession Number : ADA118883

Title :   The High-Frequency Radiation Patterns of a Spheroid-Mounted Antenna.

Descriptive Note : Quarterly rept. 29 Nov 79-29 Feb 80,


Personal Author(s) : Huang,C C ; Wang,N ; Burnside,W D

PDF Url : ADA118883

Report Date : Mar 1980

Pagination or Media Count : 85

Abstract : An efficient numerical solution for the high frequency radiation patterns of a spheroid-mounted antenna is investigated. The Geometrical Theory of Diffraction is the basic approach applied. The ray analysis in the lit region is straightforward; whereas, the geodesic paths on the surface dictate whether the shadow region solution is practical to obtain or not. Previous attempts employing calculus of variations or tensor analysis were too complicated to use. Cylinder and cone perturbation methods are presented to simulate the geodesic paths on a spheroid, which in turn can be used to model an aircraft or missile fuselage. The geodesic paths are then efficiently solved via a numerical approach, in that a cylinder and cone are developed surfaces. Good agreement between the measurement and calculation results has been obtained except when caustic effects come into play. This type of caustic effect is still an unsolved problem and is beyond the scope of the present study. This study has presented a very useful solution in approximating the geodesic paths on a spheroid, and predicting the high frequency radiation patterns for spheroid-mounted antennas. Using this perturbation approach one can extend this technique to solve for the geodesic paths on more complex convex surfaces. (Author)

Descriptors :   *Antenna radiation patterns, Antenna configurations, High frequency, Numerical methods and procedures, Diffraction analysis, Calculus of variations, Geometric forms, Perturbation theory

Subject Categories : Electrical and Electronic Equipment
      Radiofrequency Wave Propagation

Distribution Statement : APPROVED FOR PUBLIC RELEASE