We propose a new phase-modulation-combination system for the generation of arbitrarily shaped repetition rate pulses. In this system, the pulses from two electro-optic switches are modulated and interferentially combined, thereby improving the shaping resolution and narrowing the pulse width. This method allows the arbitrary tuning of pulse width, repetition rate, and temporal profile in an all-fiber configuration. The system is compatible with and can be easily embedded in other systems to achieve higher pulse energy and higher pulse repetition rate.