UWB Conformal Antennas
Abstract
Antennas currently used for VHF and UHF band operation (30-512MHz) are bulky and often inefficient. Antenna miniaturization techniques can be employed to reduce their size and improve performance. The two most common approaches are the use of dielectric material or reactive (inductive and capacitive) loading to create a slow wave structure by reducing the effective wavelength in the antenna structure. In this report the concept of miniaturizing a broadband spiral antenna using dielectric materials is experimentally demonstrated using 2" and 6" diameter spirals and further investigated using simulations. Additionally, an approach using lumped inductors and capacitors for miniaturization is also investigated. It is shown that the effectiveness of dielectric loading and reactive loading is limited by their ability to practically load the near field region of the antenna. Using such loading techniques, a miniaturization factor of nearly 2 was achieved. However, this is insufficient for operation down to 30MHz using a 6" or 15" aperture. To achieve operation down to 30 MHz using a 6" or 15" aperture, miniaturization factors of 11 and 4.5 are necessary. To increase the miniaturization and overcome these limitations, methods are introduced that will allow for the antenna fields to be confirmed closer to the antenna so that they can be loaded more effectively using practical loading geometries.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jul 01, 2004
- Accession Number
- ADA425105
Entities
People
- Boris Krämer
- C.-c. Chen
- G. Kiziltas
- J. H. Holloran
- John L. Volakis
- Minah Lee
Organizations
- Ohio State University