Source Geometry Optimization for Hemispherical Radiation Pattern Coverage

Single beam patterns radiated by linear sources degrade as their maxima points toward endfire direction. Different source geometries are, therefore, to be investigated and compared to achieve better angular coverage. We choose to perform this by analyzing the characteristics of the linear operator connecting the current source to the far field in a simplified two-dimensional (2-D) geometry through its singular value decomposition (SVD). Two indexes are introduced and found useful to achieve geometry optimization. First, the case of continuous sources is examined and then the results are extended to discrete (array) sources. It is found that, while the best solution is a conformal semicircumference source, linear sources arranged at angles provide nearly identical single beam patterns pointing in different directions to provide a hemispherical coverage.