Design of a coaxial Bragg resonator for a 250 GHz cyclotron autoresonance maser oscillator

This paper concerns the design of a new kind coaxial Bragg resonator for a cyclotron autoresonance maser oscillator, which operates in TE 11 mode at a frequency of 250 GHz. Two different Bragg reflectors with sinusoidal ripples have been employed in the resonator to improve the mode selectivity. For the upstream reflector, both the outer wall and the inner rod are properly corrugated to suppress the generation of the spurious modes; whereas only the outer wall is corrugated for the downstream reflector to provide a narrow bandwidth, which is favorable to only one high- Q axial mode. Numerical calculation is carried out to demonstrate the peculiarities of the designed resonator.