Accession Number : AD0826367

Title :   PROPAGATION IN AN OPEN, PERIODIC, IRIS WAVEGUIDE,

Corporate Author : ILLINOIS UNIV AT URBANA ANTENNA LAB

Personal Author(s) : Brown, G. S. ; Mittra, R.

Report Date : OCT 1967

Pagination or Media Count : 101

Abstract : The existence and character of modal fields on a structure consisting of an infinite periodic series of slotted metal planes are considered. The problem is two dimensional since no variation in one transverse coordinate is assumed. Integral equations involving the unknown field in one slot or iris and the propagation constant are formulated for both types of field polarization with the aid of appropriate Green's functions. The integral equations are reduced to infinite matrix equations via the application of Galerkin's method in the Fourier transform domain. The so-called odd and even radial Mathieu functions of the first kind are found to yield a rapidly convergent series representation for the iris field and the appropriate polarization. Individually, these particular functions satisfy the required boundary conditions thus giving a consistent representation for the slot field. The elements of the matrices in the determinantal equation involve integrals of the Mathieu functions but may be quite readily evaluated by an application of the method of saddle points. For a given polarization, the first two modal propagation constants and slot field distributions are computed for both even and odd field symmetry. (Author)

Descriptors :   *PROPAGATION), (*WAVEGUIDE IRISES, (*WAVEGUIDES, FIELD THEORY), MILLIMETER WAVES, INTEGRAL EQUATIONS, POLARIZATION, GREEN'S FUNCTION, SPECIAL FUNCTIONS(MATHEMATICAL), BOUNDARY VALUE PROBLEMS, INTEGRAL TRANSFORMS.

Subject Categories : Electrical and Electronic Equipment
      Radiofrequency Wave Propagation

Distribution Statement : APPROVED FOR PUBLIC RELEASE