Experimental study on compact, high-gain, low SAR single- and dual-band patch antenna for cellular telephones

The presence of the human head and hand significantly alter the performance of cellular telephones. A considerable fraction of the power (30-70 percent) is generally absorbed by the human body, causing SAR concerns and drastic reduction in antenna efficiency. The use of high-gain, broad-band, microstrip patch antenna would alleviate the problem, leading to low SARs without decrease in radiating performance of the cellular telephone. We present experimental and numerical results on one single-band and one dual-band microstrip patch antennas (covering the wireless bands, i.e. 825-895 and 1850-1930 MHz) designed in our laboratory. Results show that these antennas, mounted on a box simulating the handset, are characterized by radiating performance comparable to, or better than, typical cellular telephones. Moreover, the patch antenna handsets induce very low SARs in the human head compared to those of similar handsets equipped with typical whip antennas. Because of the reduced absorption in the head and resulting lower SARs, the patch antennas will require less power leading to longer battery life.