Multiple Antenna Systems With Inherently Decoupled Radiators

In multiple antenna systems mutual coupling needs to be minimized. We propose an alternative novel decoupling technique, investigating several multiple antenna configurations for small handsets through measurements and numerical simulations. The influence of different novel designs on performance metrics such as total loss, antenna isolation and envelope correlation coefficient are investigated. By varying antenna impedance bandwidth and antenna location with respect to the handset, both planar inverted F antenna (PIFA) and inverted F antennas (IFA) were investigated in different UMTS frequency bands in proximity with the user´s body. Results show that antennas may experience very different losses and envelope correlation coefficients depending on their relative position with respect to the handset, as the influence of the user´s hand is not symmetrical in most cases. Narrow-band antennas are inherently decoupled when integrated on the same handset, while also other parameters such as frequency duplex distance and interaction with the user´s body influence the mutual coupling.