Background With the rapid development of high power microwave technology, planar array antennas with high-power capacity, high aperture efficiency and low profile characteristics become more and more attractive.

Purpose To improve the performance of high power microwave planar array antennas, a mode fission antenna with low profile applied to the C band is proposed to enhance the power capacity and aperture efficiency.

Methods The simulation and experimental research were conducted on this form of antenna.

Results The simulation results show that the aperture efficiency of the designed mode fission antenna is as high as 95.2%, and the power handling capacity is higher than 200 MW/m². The low power and high power experiments reveals that, the port reflection is lower than −20 dB at the center frequency of 4.3 GHz, with realized gain of 34.6 dBi and aperture efficiency of 91.9%. Power handling capacity is higher than 200 MW/m², radiation pulse width not less than 50 ns.

Conclusions It achieves higher aperture efficiency while ensuring power capacity, and has high potential for application.