Abstract: In order to improve the frequency doubling coefficient and reduce the complexity of the system of the millimeter-wave signal generation in the radio over fiber, a filter-free 16-frequency millimeter-wave signal generation scheme based on the dual-parallel Mach-Zehnder modulator(DPMZM) and polarization multiplexing is proposed. The generation mechanism of frequency doubling scheme in ideal condition is deduced. In the simulation, the influence of non-ideal factors such as modulator modulation index, extinction ratio, angle shift of electric phase shift, polarization device angle drift on the optical sideband suppression ratio(OSSR)and the radio frequency spurious sideband suppression ratio(RFSSR) is analyzed. The results show that when the value range of each parameter is reasonably set, the corresponding saturation values of OSSR and RFSSR are 29. 88 dB and 23. 9 dB. The scheme simplifies the system model of 16 frequency doubling to a certain extent and the millimeter-wave signal generated has high performance and good spectrum purity, which has certain reference value for the practical system design, and provides a new way for the development of microwave photonics.