1. 1 DIAGONAL MULTIMODE HORN ANTENNAS DIAGONAL MULTIMODE HORN ANTENNAS

2. 2 Multimode Horn Antennas ( some applications ) multimode excitations are used : to obtain equal beam-widths in the E and Hplanes to reduce the side lobe levels

3. 3

4. 4 Calculation of Aperture Fields Modes: TE 01 mode TE 10 mode (orthogonal counterpart of TE 01 ) These modes are added vectorially to create the diagonal mode

5. 5 From the electric field vector, it is clear that *only Ex exists for one mode and *only Ey exists for the orthogonal mode. The spatial variation of Ex and Ey is given by propagating wave function Calculation of Aperture Fields

6. 6 Calculation of Far-Fields

7. 7 similarly y-component x-component

8. 8 the electric field amplitude in the far field for principal planes Calculation of Far-Fields

9. 9 the electric field amplitude in the far field for the ± 45 o planes Calculation of Far-Fields

10. 10 References A.W. LOVE “The Diagonal Horn Antennas” Microwave J., Vol. V, pp. 117-122, Mar. 1962 Constantine A. Balanis, ‘Antenna Theory, Analysis and Design’ 2nd Ed., Wiley,1997 R.E Collin, ‘Antennas and Radiowave Propagation’ McGraw- Hill, 1985