Dielectric-Loaded Conformal Slot Antennas for Telemetry Applications

Abstract

The design and construction of a variety of slot antennas that conform to conical, ogival and cylindrical surfaces are described. These antennas are dielectric-loaded cavities or waveguide radiators with very thin metallic walls that are efficient and simple to fabricate. Some are fabricated from low-loss copperclad dielectric materials. Other designs involve the process of electroless copperplating over a dielectric substrate to form the cavity. Radiating slots are cut after the cavity configuration is formed. The feasibility of these antenna designs and the construction methods employed have been fully demonstrated. Many important advantages are derived from the use of the technique. It is highly suitable for the design of telemetry antennas in the L-band region. Antennas of this type lend themselves to flushmounting and can be easily designed to radiate through a dielectric window. Design parameters are easily controlled, thus allowing good overall electrical performance with consistent and reliable results for production quantities. Because they can be constricted to conform to the structures on which they are mounted, very good radiation pattern coverage is obtainable. Most models tested have good voltage standing-wave ratio characteristics and are capable of operating over at least a 101, bandwidth. Complete antenna systems with varied configurations have been designed in the frequency range from 1.0 to 2.5 GHz, yielding highly satisfactory results and at very low cost.