Abstract: A MEMS patch antenna which can be integrated with RF module easily was designed to improve the bandwidth and gain of the traditional microstrip antenna. The equivalent dielectric constant of substrate of the microstrip antenna was optimized to greatly increase the bandwidth of the antenna by a high resistivity silicon being bonded to a low resistivity silicon to form a double-layer silicon substrate under the MEMS technology. Defected ground structure was also used on ground plane in order to restrain the harmonic radiation of antenna. Based on the above aspects, a 22 antenna array was designed with a center frequency of 10 GHz. The simulation results show that the antenna array has an impendence bandwidth of 15.9% and a gain of 10.9 dB, significantly better than traditional antennas and meets the anti-interference requirements of antennas in the fuze.