Patent ID: 7456577

Claim:
A microwave tube for generation of an electromagnetic wave with frequency F, the microwave tube comprising: mechanical means for varying the frequency F, wherein said mechanical means are composed of: a set of rings defining a periodic structure inside the tube; and mechanical means for displacing said set of rings with respect to each other while maintaining a periodicity for the periodic structure during displacement of the set of rings, wherein the mechanical means for displacing the set of rings comprises: a set of electrical contacts between the set of rings; and one set of pins, each pin of said one set of pins respectively being firmly connected to a corresponding ring of the set of rings, the tube being provided with at least one longitudinal slit through which each one of the pins of the one set of pins can pass in the wall of the tube, an outer ring external to the tube comprising a set of slits, each slit in the outer ring allowing the passage of a corresponding pin of the one set of pins, each slit in the set of slits having a different inclination for each corresponding ring of the set of rings so as to maintain a periodicity for the different rings of the set of rings during displacement of the set of rings.