Simulation Design of Dual-Band High-Power Microwave Transmission and Radiation Antenna

This paper aims to address the compact transmission and radiation requirements of a dual-band nested high-power microwave (HPM) source (8.4 GHz/2.0 GW at X-band, 30.6 GHz/0.9 GW at Ka-band). We have conducted simulation-based optimization on dual-band microwave support rods and a nested radiating horn. Based on the coaxial waveguide characteristics of X-and Ka-band, we used 15 dual-row support rods (spaced at 5λX/4) and 23 dual-row rods (spaced at 13λKa/4). This enables efficient TEM mode transmission (S21 > 0.99) with a power handling capacity of 18.9 GW (X-band) and 1.4 GW (Ka-band). The radiation system has a nested design. The Ka-band undergoes mode conversion to radiate in TM01 mode, while the X-band is transmitted via coaxial TEM mode and then radiates in TM0n mode. Simulation shows that both bands have reflection coefficients below - 30 dB, with radiation gains of 19.1 dBi (X-band) and 15.8 dBi (Ka-band). The dual-frequency horn has isolation above 50 dB and meets the power handling capacity requirements. Additionally, the far-field multilobe characteristics of TE11/TE21 modes aid experimental mode diagnosis. Overall, this design offers key technical support for compact multi-frequency HPM systems.