# CORREC

## Analysis of Rectangular Waveguide and Horn Structures

### Applications of CORREC

The program suite, CORREC, can be used to analyse rectangular waveguide and horn structures such as pyramidal horns, corrugated horns, dual mode horns, step transformers, tapers, etc (see below). Corrugated waveguide low pass filters and and polarisers can also be analysed.

### Modelling Method Used By CORREC

The mathematical basis of the analysis program exploits a modal matching technique. The structure to be analysed must be modelled as a number of discrete rectangular waveguide segments supporting propagating as well as evanescent TE and TM waveguide modes. A scattering matrix approach is employed to determine the complex coefficients of the modes at the aperture of the horn. The far field radiation patterns are then obtained by summing individual radiation patterns of TE and TM modes at the aperture, weighted by the complex modal coefficients.

The dominant TE10 mode excitation is assumed.

### Examples

Figure 1 below shows the geometry of a dual polarised rectangular horn and Figure 2 shows the radiation patterns at 11 GHz.

Figure 3 below shows the geometry of an E-plane corrugated rectangular horn and Figure 4 shows the radiation patterns at 9.5 GHz.

### Program Contents

The program suite CORREC consists of a pre and post processor program PREPREC and an analysis program CORREC.

Input data files for CORREC can be prepared interactively using PRE- PREC which incorporates many screen editing facilities. A waveguide/horn profile generator is also built into PREPREC to enable repetitive generation of structures such as corrugated horns and tapers by simply altering a few key parameters. The profile of the resultant structure can be viewed and modified interactively prior to analysis. The computed radiation patterns of the horn can also be displayed on the computer screen and each radiation point can be examined.

CORREC was developed by Dr.S.M.Tun of S.M.T. Consultancies Ltd.

## Platforms

CORREC is available on these platforms.

Figure 1 Geometry of dual polarised rectangular horn as created by CORREC. This is a screen dump. The table of parameters on the right hand side refers to the section of the horn outlined in red.

Figure 2 Principal plane radiation patterns of the rectangular corrugated horn of Figure 1 at 11 GHz

Figure 3 Screen dump of E-plane corrugated horn. The tabulated parameters on the right hand side refer to the section of the horn outlined in red.

Figure 4 Principal plane radiation patterns of the horn of Figure 3 at 9.5 GHz