NASA Logo

NTRS

NTRS - NASA Technical Reports Server

Back to Results
Design considerations for an archimedean slot spiral antennaThe design goal is to develop a 118-157 MHz, vertically polarized, low-profile (or conformal) antenna as a replacement for VHF AM blade antennas on aircraft. This design is to be arrived at by scaling the dimensions of an antenna designed for a center frequency of 1.1 GHz. The design prior to scaling may have the following maximum dimensions: diameter less than 3.70 in. and thickness less than 0.50 in. Although a four-arm spiral design was originally suggested, a two-arm spiral may also be used, as both mode-1 and mode-2 (sum and difference) radiation patterns aren't required. While a four-arm spiral can easily be designed should both sum and difference patterns be required, the two-arm design will provide the required sum pattern and simplify the design problem somewhat: only one feed is required, and the feed area geometry is more straightforward. Polarization requirements dictate that a slot spiral be used, as opposed to a wire spiral. Two similar radiating structures were considered. The first is the standard archimedean spiral antenna. The second is a hollow archimedean spiral antenna, essentially a standard archimedean spiral with the inner portion removed.
Document ID
19950013382
Document Type
Other
Authors
Nurnberger, Michael W. (Michigan Univ. Ann Arbor, MI, United States)
Volakis, John L. (Michigan Univ. Ann Arbor, MI, United States)
Date Acquired
September 6, 2013
Publication Date
January 1, 1995
Publication Information
Publication: Simulation of Thin Slot Spirals and Dual Circular Patch Antennas Using the Finite Element Method with Mixed Elements
Subject Category
COMMUNICATIONS AND RADAR
Distribution Limits
Public
Copyright
Work of the US Gov. Public Use Permitted.

Related Records

IDRelationTitle19950013331Analytic PrimaryThird CLIPS Conference Proceedings, volume 2