A novel technique to achieve optical frequency up-conversion in millimeter wave (mm) band without any local microwave oscillator is proposed. It is hard to directly get mm band carrier frequency because the efficiency of mode-locking decreases as the carrier frequency increases. Thanks to dynamic charge carrier density responses during the injection locking of Febry-Perot laser diode (FP-LD), the wavelength of the leading part of carrier is red-shifted while that of falling part is blue-shifted. With a suitable negative dispersion device, the carrier pulse is compressed and its 2nd harmonic is greatly enhanced. Thus it is feasible to make the radio over fiber(RoF) frequency up-conversion in mm band. Subcarriers of 13.9 GHz are obtained from 2 Gb/s nonreturn-to-zero(NRZ) signal injection while that of both 13.9 GHz and 15.4 GHz are obtained from 2.5 Gb/s NRZ signal injection into FP-LD. And the 2nd harmonic at 27.8 GHz and 30.8 GHz are enhanced by more than 20 dB, 25 dB and 23 dB, respectively. The simpleness and tunability of the proposed scheme make it a great candidate for low cost mm band RoF frequency upconversion up to 60 GHz.