The authors propose an injection-locked millimeter wave generator based on a field-emission mechanism according to the previous successful designs of the terahertz and millimeter wave devices. The design of this injection-locked device has been carried out and verified by numerical simulations. A bandwidth of about 60 MHz has been obtained and agrees with the prediction of Adler's equation. The Q factor of the resonant structure is also calculated. An electronic efficiency of up to 6.7% can be achieved without any external magnetic field applied. (C) 2008 American Vacuum Society.