The main objective of this book is to develop an antenna operated at 1800MHz GSM band for mobile handset with reduced RF interference towards the user. This is achieved by altering the radiation characteristics of the monopole antenna by modifying its geometry with high impedance resonating structures like split ring resonator, single metal strip and with vertical stripes. It is found that this antenna is radiating all the three quadrants effectively with a null in the forth quadrant. A printed monopole antenna is suitably folded to make a low profile, small size folded antenna. Folding technique is introduced to achieve the compactness and to change the direction of null point. The radiation characteristic of the proposed 3D structure of the ground folded monopole antenna is also modified with a vertical strip printed at the back side of the ground plane. Experimental and simulation investigations on near field radiation characteristics are also carried out to study specific absorption rate. Antennas are simulated with SAM phantom model to estimate specific absorption rate (SAR). Experimental setup is also developed to measure normalized SAR.