The single ended circulator based on the spatiotemporal modulation(STM) will be affected by the intermodulation products(IMP) very close to the required frequency band due to the mixing between RF input and modulation signal. These intermodulation products will not only cause interference to adjacent channels, but also limit the modulation parameters. By matching two single ended circulators, the single ended circulators in the differential circulator are modulated respectively with the modulation signal of 180° phase difference, which can eliminate the IMP, so as to effectively improve the insertion loss, bandwidth and power handling of circulator, improve the performance of circulator, and significantly relax the requirement of the modulation frequency. This paper describes the basic principle of differential circulator, summarizes its circuit structure, modulation and test methods. The comparative analysis shows that BAW differential circulator exhibits excellent performance in insertion loss, isolation and power consumption, and is expected to replace ferrite circulators in most commercial systems.