Fig. 1. Schematic of FDTD cell.

Fig. 2. Local conformal grid.

Fig. 3. Time history of electric field inside a resonator.

Fig. 4. Schematic of a surface wave oscillator.

Fig. 5. Contour of the Ez inside the SWO.

Fig. 6. Time history of the electric field (a) inside the SWO with PEC and its spectrum (b).

Fig. 7. Time history of the electric field (a) inside the SWO with lossy copper and its spectrum (b).

Fig. 8. Output power from the SWO.

Fig. 9. BWO with planar structure.(a = 7.2 mm, b = 1.8 mm; l = 0.1 mm, w = 2.5 mm, h = 0.16 mm, d = 0.058 mm)

Fig. 10. Phase space of electrons in the BWO

Fig. 11. Time history of electric field in the BWO with PEC (a) and lossy copper (b).

Fig. 12. Output power from the BWO: (a) PEC ; (b) lossy copper.