The purpose of this study is to design for MOB Antenna attached on Safety Helmet using Microstrip Patch Antenna. The Patch Antenna is designed by 0.2mm FR-4 substrate with 64×64mm size. The proposed antenna is based on a Slot-ring design which cover Inmarsat(1.52 ~ 1.65GHz) and GPS(1.575GHz) frequency band. To obtain the optimized parameters, HFSS simulator is used, and the parameters are found by simulation. Antenna is designed and manufactured by optimized parameters and analysis of the result between Antenna measurement and simulation. Proposed antenna satisfied the –10dB impedance Bandwidth requirement while simultaneously covering the 1.53 ~ 1.65 GHz.