Human body coupling effects on radiation characteristics of superquadric loop antennas for pagers´ application

The influence of the human body on the antenna radiation characteristics, such as input impedance, current distribution, radiation pattern, radiation efficiency (reduced due to the body absorption), and directive gain/power gain, etc., is a important consideration for pagers´ antennas, which are usually a rectangular loop antenna. The superquadric loop is used to approximate the square loop antenna. Since a pager is usually worn on the belt, the pager antenna is in close proximity to the human body and the EM coupling effect will significantly affect the antenna characteristics. In this paper, the approach of coupled integral equations (CIE) and the method of moments (MoM) are employed to numerically simulate the EM coupling effect of the human body on the antenna characteristics of a superquadric loop. A 3-D realistically shaped man model (175 cm height) with homogenous muscle phantom is constructed for numerical simulation. Numerical results of the loop antenna radiation characteristics at 280 MHz in free space and proximate to the body are presented and compared.