In this study, an arbitrary waveform photonic generation scheme with simple structure and repeat rate tunability is proposed. The scheme consists of a dual parallel phase modulator, fiber Bragg grating, and balanced detector. The dual parallel phase modulator modulates the laser, and two optical signals obtained by fiber Bragg grating can output as square and trapezoid microwave signals via balanced detection. Meanwhile, a 90° phase shifter is used to obtain triangular and sawtooth microwave signals. By adjusting the voltage and frequency of the radio frequency drive signal, the simulation results show that the frequency of the output microwave photonic signal can achieve 10 to 25 GHz with the root mean square error (RMSE) of less than 0.33. In addition, the effects of modulation index β and 90° hybrid phase balance Δθ on microwave photonic waveform quality are analyzed experimentally. The RMSE of waveform signals is less than 0.42 when the standard value β varies by standard value ±0.15 or Δθ varies by ±3°, which verifies that the designed system has a good stability.