A ladder structure for millimeter waves

A planar structure, closely related to the stub-supported ring and bar structure, is analyzed using Fletcher's method. The computed dispersion characteristics and interaction impedances show that it should prove useful in millimeter generators. Experiments at X band have shown that oscillation bands of over 1.7 : 1 are possible working on a backward mode. Forward-mode operation with higher output powers, but with a more restricted bandwidth can also be realized.