Multilayer Reconfigurable GPS Antennas and Platform Effects

Abstract

The work reported here discusses two topics. First, the design and test of a GPS pattern reconfigurable antenna is reported. It is shown through computer simulations and measurements that the beamwidth of the antenna can be changed by turning diode switches on and off. This antenna concept was developed to minimize the effect of interfering signals incident on the antenna along the horizon. This work also shows that microstrip antennas can be fabricated with a thick substrate without the usual surface wave problem. The second topic reported here is the development of the theory of characteristic modes in the time domain. The method described here uses the FDTD technique and has a major advantage over frequency domain algorithms because the resonances of the structure can be captured in a single FDTD run. Examples are given where resonance frequencies as well as characteristic modes are found for several structures, including a printed dipole, a reconfigurable printed antenna and a log-periodic antenna. To validate the proposed method, simulated results and analytical solutions are compared and shown to have excellent agreement.

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Document Details

Document Type
Technical Report
Publication Date
Sep 01, 2007
Accession Number
ADA473901

Entities

People

  • Roberto G. Rojas

Organizations

  • Ohio State University

Tags

Communities of Interest

  • Air Platforms
  • Autonomy
  • Energy and Power Technologies
  • Space

DTIC Thesaurus Topics

  • Air Force
  • Air Force Research Laboratories
  • Antennas
  • Computer Simulations
  • Dielectric Permittivity
  • Frequency
  • Frequency Domain
  • Geometry
  • Global Positioning Systems
  • Log Periodic Antennas
  • Radiation Patterns
  • Resonance
  • Resonant Frequency
  • Simulations
  • Surface Waves
  • Time Domain
  • Waves

Readers

  • Electromagnetic Wave Scattering and Antenna Radiation Engineering
  • Phased Array Antenna Design.

Technology Areas

  • Microelectronics
  • Space