Broadband Double-Ridged Horn Antenna

Horns are widely used antennas since they have a simple construction, are easy to excite and have a large gain. They are employed for example as feed elements in satellite tracking systems or communication dishes and they serve as a standard antenna for calibration and gain measurements. Since they have a limited bandwidth, great efforts have been made to enlarge the operational bandwidth. Ridges on the side flares are introduced to extend the bandwidth, similar to the ridges in a waveguide that lower the cut-off frequency. The design of double-ridged horn antennas reaches back to the late 1950s. Figures 1 and 2 show a 3D view
 of the horn that we simulated.

Fig: Tilted front 3D view of the antenna model. 1: Feed section, 2: Ridge, 3: Wedge, 4: Lower flare, 5: Upper flare, 6: Copper strap.

Fig:  Feeding section of the double-ridged horn antenna. 1: Ridge, 2: Cavity, 3: Coaxial feed, 4: Source plane, 5: Port plane. Wedges and other parts are removed for better visualization.

The propagation of the electric field is shown at two different frequencies (ramped sinusoidal excitation) in the following movies.

    

      Fig:  Magnitude of the electric near-field at 7 GHz. 

Fig:  Magnitude of the electric near-field at 12 GHz.