Dispersion characteristics and electromagnetic properties of semicircularly corrugated slow‐wave structure for backward‐wave oscillators

Abstract

The dispersion relation of semicircularly corrugated slow‐wave structure (SCCSWS) is calculated and verified numerically using synthetic technique. The metallic periodic structure resonates at discrete frequencies when both ends of it are shorted and excited properly. From the discrete frequencies of the axial modes of the resonant cavity, continuous dispersion curve for both the fundamental and the higher order passband modes (TM01‐TM03) are generated. The generated dispersion curve is compared with the analytical results, which agree excellently with a maximum deviation of 1.33% for TM01 mode, 1.94% for TM02 mode, and 1.30% for TM03 mode. The electromagnetic field patterns of SCCSWS in both radial and axial direction are also calculated and compared with analytical field patterns. Comparative results validate both the obtained dispersion relation and field patterns of SCCSWS, which can be employed as viable alternative of the existing slow‐wave structure (SWS) in high‐power microwave devices.