A photonic approach for generating phase-coded waveform with continuously tunable carrier frequency based on cascaded Mach-Zehnder modulators (MZMs) is proposed. By setting the direct-current bias point and modulation index of the cascaded MZMs, we can select ±4 th-order optical sidebands. Finally, a phase-coded signal with a frequency multiplication coefficient of 16 can be generated at the output of the unbalanced temporal pulse shaping (UTPS) system through the controlling of the phase of the radio frequency driving signal applied to the cascade MZMs. In addition, when the dispersion values of the two linear chirped fiber Bragg gratings in the UTPS system are adjusted to be appropriate, the carrier frequency of phase-coded signal can be continuously tunable. Phase-coded signals with the carrier frequencies of 32 GHz and 19.2 GHz are generated with a 2 GHz radio frequency signal in the simulation. The simulation demonstrate the effectiveness of the proposed method, and also shows superior compression of the generated signal.