Abstract: In this paper the Specific Absorption Rate (SAR) of a microstrip antenna is presented which can be used for 4G mobile wireless communications.The proposed antenna geometry describes a inset feed rectangular patch printed over a FR4 substrate of thickness 1.6 mm and Permittivity er = 4.3. The antenna is designed with slot and simulated in CST microwave Studio electromagnetic simulation tool. The simulated antenna shows -25dB of return loss, 69.13MHz bandwidth for 2.3GHz,-30 dB of return loss, 91.55MHz for 3.5GHz and -25 dB of return loss, 102.774MHz for 4.46GHz and VSWR is less than 2. Head model is developed to calculate the SAR value. The head model is kept at a distance of 50 mm from the antenna and SAR is calculated. The SAR value is 0.06399 W/Kg for 10 gram of tissue which is well within the value specified by the FCC. So there is a 96.80 % reduction compared to the value set by FCC.

Keywords: Specific Absorption Rate (SAR), Microstrip patch antenna, Return Loss, FCC.