Publication Date:
2014-07-23
Description:
In this paper, a modified numerical method is used to investigate the mode composition of a Gigawatt-class Ka-band overmoded Cerenkov oscillator, which has been proposed and studied in our previous experiment. In the experiment, the measured angular distribution of radiation did not fit a single TM 01 mode. So the particle in cell code calculations and the antenna radiation calculations are carried out, which show a consistent picture: the dominant modes are the TM 01 mode and the TM 03 mode, and their phase relationship is constant with time; therefore, a steady radiation pattern is produced, which matches the experimental data. As a conclusion, the comprehensive analysis shows that the existing modes of the output microwave in our experiment are the first five TM 0 n modes ( n = 1–5), with corresponding power ratios of 36.64%, 0.78%, 56.26%, 5.70%, and 0.52%, and relative phase differences of 0°, 146°, 54°, 169°, and 133°.
Print ISSN:
1070-664X
Electronic ISSN:
1089-7674
Topics:
Physics
