TUNED FILTER IN A WAVEGUIDE,
Abstract
The theory of tuned optical filters is applied to waveguide filters. A rectangular (or cylindric) waveguide with walls of infinite conductivity, filled with two dielectrics separated by a perpendicular plane, is examined. The dielectrics have different dielectric constants and permeabilities. Formulas analogous to the Fresnel formulas for reflection and refraction of light by the boundary of two media are used. The main formulas are derived (on the basis of the theory of multilayer optical films) in matrix form for the reflection and transmission coefficients for the TE and TM modes. If the refractive index of one of the dielectrics is sufficiently small, its wave number can become imaginary, resulting in total reflection with nonoblique incidence. Frustrated total reflection is also found to be possible and provides a basis for constructing a narrow band tuned filter for a waveguide. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Oct 18, 1968
- Accession Number
- AD0685495
Entities
People
- P. Kard
Organizations
- National Air and Space Intelligence Center