A novel E-field eight-way cavity combiner for high-power S-band applications

Cavity combiners are critical components in high-power radio frequency (RF) systems, such as particle accelerators, radar, and communication platforms, owing to their low loss and compact structure. This paper presents a novel cavity combiner based on an azimuthally modulated pillbox cavity operating in the TM010 resonant mode. The cavity combiner presented in this work uses electric-field coupling for both inputs and the output coupler. The azimuthal modulation allows the insertion of input couplers on the same contour of electric field, overcoming the physical limitations imposed by the size and number of RF connectors in conventional cylindrical pillbox designs. The design was optimized using full-wave electromagnetic simulations, and two eight-way combiner prototypes were fabricated and experimentally tested. Measurements demonstrate a 0.1 dB bandwidth of 15.8 MHz. The proposed structure is simple to fabricate, scalable, and suitable for power combination in S-band applications, making it a promising candidate for particle accelerator and radar applications.