Waveguide Gunn diode oscillator with harmonic tuning

Claim 1

A waveguide Gunn-diode oscillator comprising a main cavity extending for the entire length of the waveguide and housing a Gunn-diode mounted perpendicular to the direction of extension of the waveguide; and means for regulating the tuning frequency of said main cavity further including an auxiliary cavity branching laterally from said main cavity and in communication with it through a passage therebetween, said auxiliary cavity being positioned on an equiphase plane with said Gunn-diode in said main cavity, said auxiliary cavity having dimensions such as to impede the entry into said auxiliary cavity of the fundamental component of a signal present in said main cavity and to permit the entry of the harmonic components of said signal, a column housed parallel to said Gunn-diode in a symmetrical position with respect to said Gunn-diode in said main cavity, an antenna wire traversing said passage of communication between said main cavity and said auxiliary cavity, and having one extremity terminating against a part of said auxiliary cavity and the other extremity attached to said column, constituting a variable reactance double gate element positioned in series with said Gunn-diode, harmonic tuning means housed in said auxiliary cavity suitable for causing a variation in the load impedance seen by said Gunn-diode at the frequencies of the harmonic components of said signal in said main cavity, by means of variation of the reactance of said auxiliary cavity to the harmonic components.