Potential and capabilities of two-terminal devices as millimeter- and submillimeter-wave fundamental sources

InP Gunn devices and GaAs TUNNETT diodes yielded RF power levels of, for example, >80 mW at 152 GHz, >10 mW at 202 GHz, and >1 mW at 315 GHz. They are among the most promising candidates for all-solid-state and low-noise RF power generation at high millimeter-wave and submillimeter-wave frequencies. These recent experimental results are compared with performance predictions, and the capabilities of other potential solid-state fundamental sources for this frequency range such as, IMPATT diodes and RTD´s are discussed.