Changes

This is a very large The size of the computational problem with a domain size of in this case is about 1720λ₀ × 1720λ₀ × 1115λ₀. The computational domain is terminated in convolutional perfectly matched layers (CPML) from all six sides. To keep Using the simulation manageable, a same mesh density of 15 cells per effective wavelength is adopted. [[EM.Tempo]]'s mesh generator uses an initial tessellation of the physical structure to accelerate the Yee mesh generation. To get a smooth mesh of the curved surface of the paraboloid, a curved edge angle tolerance of 10° is used. A very large FDTD grid (550 636 x 548 632 x 350443) is generated. The Yee mesh with a total of the reflector-horn combination is shown in the figure below178,064,736 cells. The FDTD simulation was run on the same ASUS laptop computer. The simulation involved a total of 105,490,000 Total cells and converged after 89,850 275 time steps. The total simulation time was 155 235 minutes including both the FDTD time marching loop and computation of the full high-resolution 3D far-field radiation pattern at a resolution of 1° along both the azimuth and elevation directions.

 636x632x443, 178064736 Total cells 9275 235 minutes The figure below shows the db_scale dB-scale 3D far-field radiation pattern of the larger parabolic reflector with the pyramidal horn feed. As you can see from the figure, the value of the directivity has not changed significantly from the previous case due to the presence of the horn feedincreases by about 3.5dB. However, the perfect circular symmetry of the pattern in the case of the short dipole feed is now all but gone.