The use of a combined embedded modulated scattering technique, utilizing a PIN diode-loaded dipole probe, and near-field microwave nondestructive testing technique, utilizing an open-ended rectangular waveguide, has been investigated as a means for determining the complex dielectric constant in which the MST probe is embedded. For this, the formulation of the forward problem of calculating the modulated reflection coefficient, measured at the aperture of the waveguide, is presented here, This formulation is based upon the reciprocity theorem for two antennae, and utilizes the near-field radiation pattern of a rectangular waveguide aperture and current distribution along the length of a dipole antenna. This formulation is verified with measured values as a function of location, load impedance and surrounding media. Finally, potential improvements, considerations, and the use of an inversion routine is discussed.

Meeting Name

20th IEEE Information and Measurement Technology Conference (2003: May 20-22, Vail, CO)


Electrical and Computer Engineering

Keywords and Phrases

Electric Impedance; Nondestructive Examination; Permittivity; Rectangular Waveguides; Theorem Proving; Dielectric Materials; Directional Patterns (Antenna); Probes; Scattering; Semiconductor Diodes; Testing; Waveguides; Lossy Materials; Dipole Antennas; Antenna Measurement; Antenna Theory; Aperture Antennas; Complex Dielectric Constant; Loaded Antennas; Microwave Non-Destructive Testing; Modulated Scattering Techniques; Near Field Radiation

International Standard Book Number (ISBN)


International Standard Serial Number (ISSN)


Document Type

Article - Conference proceedings

Document Version

Final Version

File Type





© 2003 Institute of Electrical and Electronics Engineers (IEEE), All rights reserved.

Publication Date

01 May 2003