Analysis of a field generated by an electromagnetic impulse simulator - The effect of a dipole horn deformation and a numerical study of interactions in a horn-type simulator

The behavior of antennas used for simulating nuclear EMP radiation in a test volume is discussed numerically. Three configurations, a horizontal dipole, a dipole-horn combination, and a horn simulator functioning at 1, 7, and 50 MHz are examined. The horn antenna is shown to emit the most homogeneous EMP field due to its compact form but its diminutive size raises the possibility of coupling with the test object. The currents induced on the image plane are treated with a two-dimensional model, with the simulator treated as a nonuniform waveguide. The model is judged useful for evaluating interactive effects on the rise time and the behavior of the exciting field.