A novel design of modulator for Chinese Digital Terrestrial Multimedia Broadcasting Standard is presented. Different from the traditional system of digital TV modulator, a simplified GPS/Compass2 dual timing receiver is embedded into the Single Frequency Network(SFN) block, which is removable and independent from the modulator. With this modification, the timing availability and the feasibility of switching between Multi- Frequency Network(MFN) and SFN mode is increased and meanwhile the costs are reduced. The lab tests are based on the prototype of this modulator, which is assembled with existing mature chips and modules, the results show the performance meets the Chinese National Standards on modulators and SFN applications.