Cold test of metallic photonic crystal high power microwave mode converter

A metallic photonic crystal loaded transmission line is studied, and a metallic photonic crystal type TEM-TE11 mode converter which is suitable for narrow band high power microwave application is designed according to its electromagnetic properties. Metallic photonic crystal is partially filled along azimuthal direction in the device to achieve phase-shifting. A three-row structure is designed and simulated by commercial software CST Microwave Studio. The simulation results show that its conversion efficiency is 99% at the center frequency 1.57 GHz. In the frequency range of 1.533-1.609 GHz, the conversion efficiency exceeds 90%, with a corresponding bandwidth of 4.8%. A TEM mode excitation and a horn antenna is fabricated and the performance of mode converter is tested. The results confirm the design.