High-Power Submillimeter Wave Solid-State Sources

The development and measurements of solid-state active multiplier sources for DNP-NMR experiments is described in this paper. The sources utilize power-combined Schottky diode frequency doublers as the final two stages. 250 mW output power was measured for two complete sources, one at 250 GHz and a second at 262 GHz. Using a 1.3 mm probe, DNP enhancements of 115-120 were measured.