The diagonal horn as a sub-millimeter wave antenna

The far-field radiation pattern of a diagonal horn has been calculated by aperture integration. The radiation patterns for a 4*4 diagonal horn array, measured at 100 GHz, agree very well with theoretical predictions. The aperture electric field was also expanded into Gauss-Hermite modes. The results indicate that the fraction of the power radiated into the fundamental Gaussian mode is about 84%. About 10% of the power is radiated in the cross-polarized component.>