VHF-UHF Phased Array Techniques. Part I. Calcomp Studies of Linear Arrays with Non-Uniformly Spaced Isotropic Elements.
Abstract
This report contains information obtained by numerous computer studies of linear arrays of isotropic elements. A large range of numbers of elements were used. Various formulations were used to provide control on the degree of non-uniformity of spacing. Provision was made so as to provide a gradation in the illumination of the various elements used. It was found that a simple exponential relation provided illumination corresponding simultaneously to a Tchebyscheff type radiation pattern. It was decided that for practical purposes some restraint should be provided on the grading of the slot illumination from the center slot to either extreme end slot. Therefore, in some of the studies utilizing an exponential variation of illumination, an arbitrary limit was imposed which required the illumination on the end slot to be either 9 or 12 dB below that of the center slot. Considerable work was done on an optimization process, which has been classified as the method of steepest descent. In the steepest descent method a change in spacing is made in the direction that causes the most rapid rate of change (reduction) in the difference between a prescribed radiation pattern and the obtained radiation pattern. In other words, the change to be made was always in the direction so as to decrease the error or difference between the two patterns most rapidly. In applying this optimization procedure it was decided that it was appropriate to start with an array already reasonably well designed.
Document Details
- Document Type
- Technical Report
- Publication Date
- Nov 01, 1973
- Accession Number
- AD0918224
Entities
People
- Jess B. Scott
- John A. M. Lyon
- Mohamed A. Hidayet
- Philip H. Fiske
Organizations
- University of Michigan