Abstract: The present invention comprises a modular microwave source comprising a novel electromagnetic oscillator based on a modified Blumlein architecture with an integrated antenna. In one or more embodiments, the invention comprises a triplate Blumlein in which the plates are configured and arranged to act as a waveguide and antenna. In one or more embodiments, high-permittivity dielectric materials are disposed between the center plate and one or both of the top and bottom plates to increase the energy storage and lengthen the duration of a damped sinusoid output. In one or more embodiments, photo-conductive semiconductor switches are disposed between the center plate and one or both of the top and bottom plates to act as high-speed switches. In one or more embodiments, a plurality of the modular microwave sources of the invention are arranged in an array, creating a compact, tunable, high-power microwave source suitable for mobile applications.