Orthogonal MIMO Antennas for Compact Cellular Handsets
The authors propose a novel compact MIMO antenna system for small handsets, based on two different types of antennas - a small loop and the MB antenna. The MB antenna is an enhanced dipole antenna, which can be implemented as internal antenna in a compact cellular handset. Similar to conventional dipole, MB is an electrical antenna; and the small loop is a magnetic antenna. It is shown that using these antenna one can create a compact MIMO system, with small mutual coupling between the antennas, even when the distance between them is smaller. They also present a new method for increasing the radiation efficiency of small loop antennas at frequencies higher than 470MHz. Simulations results show that the mutual coupling between MB and small loop antennas is low.