A GW Level High-Power Radial Line Helical Array Antenna

High-power radial line helical array antenna is a novel antenna developed to realize directional radiation of high-power microwaves. This antenna directly accepts an azimuthally symmetric output of a high-power microwave source and radiates circularly polarized microwave with a boresight peak. It has a high efficiency, a compact structure, and a notable power-handling capacity. Starting from its fundamental design theory, an antenna prototype consisting of 48 elements is proposed. Numerical simulation and experimental measurement are accomplished for the prototype. In the range of 3.7-4.1 GHz, the experimental result shows an antenna VSWR of below 1.2, an antenna gain of over 23.2 dB, an aperture efficiency of more than 65%, and an antenna axial ratio of below 1.6 dB. In addition, the high-power experiment proves that this antenna has a power-handling capacity of more than 1 GW.