Compact high-capacity devices of microwave power combination

Abstract

Compact 2-way and 4-way high-power microwave (HPM) waveguide combiners to realize coherent microwave combination were theoretically designed and proof-of-principle experimentally tested. Symmetry boundary is used to simplify the optimization course and design the structure. A central spherical crown with special spatial position and radius was used to realize the low return loss of each port and high transition efficiency from the incident TE 10 modes to the combined TE 11 mode, moreover, to prevent the high E-field enhancement for achieving high power capacity. The schematic structure and E-field snapshot of the two-way and four-way HPM power combiner from TE 10 to TE 11 mode is illustrated in Fig. 1 and Fig. 2. Moreover, shorted stubs at bottom replaced the spherical ball realize much higher capacity and the function of four-way TE 10 -TM 01 mode power combination, as illustrated in Fig. 3. The major sizes of the combiners are as small as λ3. The theoretical and experimental S-parameters are basically consistent with each other, and the multi-channels of HPM combiners are effectively isolated with each other to avoid the inter-modulating among the HPM sources. The HPM experiment was carried out, and the power capacity of the HPM combiner was demonstrated to reach multi-gigawatts.