Focal Region Characteristics of Focused Microwave Array Antennas.
Abstract
Fields in the focal region of a focused microwave aperture or array antenna are examined thru detailed calculations. Transverse near field patterns are well behaved with only slightly higher closest sidelobes, and with a rapid sidelobe falloff. Peak axial power density available from an aperture is a function only of distance, but the relationship is non-linear. This relationship and simple formulas alloy system tradeoffs of aperture size, frequency, focal distance and peak power density to be made. Effects of aperture amplitude taper are investigated: uniform excitation gives comparable axial and transverse subsidiary lobes, and is probably the best choice. Taylor tapers give low sidelobes but high forelobes and aftlobes, plus a modest gain degradation. Inverse tapers give low forelobes and aftlobes but very high sidelobes and large gain degradation. A brief comparison of Gaussian, Romberg, and summation calculation methods is given. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Sep 09, 1983
- Accession Number
- ADA138557
Entities
People
- R. C. Hansen