Discrete monotron oscillator having one-half wavelength coaxial resonator with one-quarter wavelength gap spacing

A microwave oscillator comprising:

• a cylindrical outer conductor;
• a cylindrical inner conductor concentric with and within said outer conductor, where said outer conductor and said inner conductor define a half-wavelength resonant coaxial microwave cavity therebetween operating in fundamental TEM mode for microwave oscillation, said inner conductor further defining a drift tube space therein for propagating an electron beam input thereto;
• said inner conductor defining a modulating gap and an extraction gap, said extraction gap being electrically spaced one quarter wavelength downstream of said modulating gap, said modulating gap and said extraction gap each connecting said coaxial microwave cavity with said drift tube wherein energy for said microwave oscillation is extracted from said electron beam at said extraction gap and said microwave oscillation modulates said electron beam at said modulating gap.