A photonic approach of frequency-octupling microwave signal generation using a si ngle polarization modulator (PolM) is theoretically investigated and experimentally verified.High order optical sidebands are generated under the condition of large-signal modulation.By carefully con trolling the polarization controller (PC) before the polarizer,only even-order sidebands are kept.The second-order sid ebands can be suppressed completely by adjusting the modulation depth (RF power level),while the fourth -order sideband power is significantly higher than those of the sixth-order sidebands and other high o rder sidebands simultaneously.Then an interleaver is adopted to suppress the optical carrier and the sixth ord er sidebands,so that the fourth-order sidebands are preserved.A frequency octupling microwave signal ca n be obtained by beating the two fourth-order sidebands at the photodetector (PD).The simulation platform and e xperiment system are established based on the theoretical analysis,and an interleaver with a channel spacing of 25or 50GHz is utilized.A continuously adjustable microwave si gnal with frequency oct upling is obtained within four different frequency ranges by making full use of the periodic filtering characteristics of the interleaver.The experimental results are in line with the theoretical analysis,so the feasibility o f the proposed scheme is verified.