The spherical near-field geometrical theory of diffraction (SNFGTD) method is an extended aperture method by which the near field from an antenna is computed on a spherical surface enclosing the...

Papers

01

Feb

1987

Authors:

The spherical near-field geometrical theory of diffraction (SNFGTD) method is an extended aperture method by which the near field from an antenna is computed on a spherical surface enclosing the...

04

Nov

1986

Authors:

Reflector antenna surface distortions may be slowly varying, rapidly varying, systematic or random. Typical examples of each of these types of surface distortions are presented and their...

11

Jun

1986

Authors:

The still increasing requirements to satellite reflector antennas, in particular with respect to such parameters as cross polarisation and side lobe level, imply a demand for fast and accurate...

10

Jun

1986

Authors:

Although geometrical optics (GO) is an asymptotic theory describing electromagnetic fields of infinitely high frequencies only, it has for several years constituted the foundation for synthesis...

01

Jun

1985

Authors:

Modern communications satellites are equipped with high gain reflector antennas with contoured beams for various purposes. A contoured beam of complex cross section is generated by exciting...

01

Jun

1984

Authors:

The paper presents various methods for the calculation of the field reflected from a subreflector in a dual reflector antenna system. It is demonstrated that the physical-optics (PO) solution...

01

Oct

1983

Authors:

Two transformations for accelerating the convergence of infinite M-dimensional series are presented. They are generalizations of Shanks' *e- *transformation and Levin's one-dimensional...

01

Aug

1983

Authors:

A waveguide polarizer with resonant notches in a septum is investigated. The Wiener-Hopf technique is employed to derive theoretical design data and the results are compared to experiments for a...

01

May

1977

Authors:

The caustics for the singly diffracted rays from a circular disk are investigated when the rays emanate from a source which is placed off the axis of the disk. Either two or four singly diffracted...

02

Oct

1975

Authors:

The near-field and the far-field patterns from the high-gain S band antenna on the METEOSAT are calculated by the geometrical theory of diffraction. The far field is transformed into the near...