One port and traveling-wave masers using coupled cavities

Analysis predicts that the gain-bandwidth product of a single cavity maser is fixed by the material parameters and the filling factor. Kuyl has shown that the negative L and C of the solid-state maser may be used to advantage in increasing the gain-bandwidth product of a coupled cavity maser. The present paper describes the experimental verification of this. phenomenon for both one port and traveling-wave masers using coupled cavities. The experiments were conducted at X-band with active solid ruby resonators. The ruby was operated in the push-pull mode with a magnetic Q of 80. The gain-bandwidth product of a single cavity maser of this type is 100 Mc. This value is increased to 250, 450 and 1000 Mc for amplifier gains of 20, 30 and 40 db respectively, when two active coupled cavities are used in a one-port maser. Note that the gain-bandwidth product is not constant but depends upon the magnitude of the gain.