MEMS-based CPW-fed unidirectional antenna array with planar air bridges is proposed in this paper. The performance of the CPW-based feeding network is improved with air bridges fabricated at the discontinuity of T-junctions and bends in the CPW-based feeding network. The simulated impedance bandwidth is from 34.4 GHz to 35.9 GHz with S11<;-10 dB. By adding four reflecting metal patches with circular slot in the center, the simulated gain of the antenna increases to 12.2 dB. Ansoft HFSS, a high frequency structure simulation software based on the finite element method, is used to simulate and optimize the performance of the antenna array.