Design of an Efficient UWB Rectangular Microstrip Patch Antenna with Reduced Specific Absorption Rates (SAR)

Nowadays, the demand for compact, high, wide bandwidth and, a low-cost antenna has increased rapidly. An antenna is a transducer that converts electrical signals to EM waves and radiates into space, The performance of an antenna is measured by its parameters namely the gain, the return loss, VSWR etc. There are several types of antennas available but the microstrip patch antennas are widely used for many applications because of its low profile, lightweight, low cost, feed-line flexibility, versatility, ease of fabrication etc. Even though it has several advantages, it suffers from major drawbacks namely narrow bandwidth, low gain, high return loss. In order to overcome these drawbacks, FR-4 materials are used. Specific absorption rate (SAR) is a measurement for observing the radiation absorbed by human body or tissue when in the electromagnetic field. It is defined as the power absorbed per mass of tissue and has units of a watt per kilogram. SAR is typically averaged either over the complete body or over a small sample volume (typically 1g or 10g of tissue). For evaluating the antenna performance, the gain, VSWR and the return loss were calculated for the proposed antenna and the proposed antenna provides the peak the gain of 4.51dB at 10.846GHz and also the SAR value of 0.00117W/Kg are evaluated for 1g of tissue for the proposed antenna. The human phantom model and the proposed antennas are designed using CST (Computer Simulation Technology) microwave Studio Tool.