Finite-difference time-domain technique for antenna radiation

The finite-difference time-domain (FD-TD) technique is used to predict the radiation pattern of antennas mounted on ground planes, either perfectly conducting or of composite material, and other complex structures. The results obtained using the FD-TD technique are compared with results using the geometrical theory of diffraction (GTD) and measurements. The normalized power pattern of a quarter-wavelength monopole on a square perfectly conducting ground plane is displayed. In addition, results obtained using a circular perfectly conducting ground plane are exhibited. The FD-TD method predicts extremely well, as does the GTD, the ring source contributions of the circular ground plane which reflect in higher intensity lobes near the axis of the system ( theta =0 and 180 degrees ) as compared to those of the straight-edge ground plane.<
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