Integrated handset antenna with low absorption and handset antenna diversity

There are several goals for the design of integrated antennas for handportables. One is to obtain high antenna performance due to the limited power available, and this goal can be translated into questions of matching, polarization, and mean effective gain seen in the context of practical ergonomic use of the handset. The second goal which has received increasing attention is absorption in the human head. In the future it can be expected that more than one antenna be included in the handset, since this will improve a critical link by offering diversity. The diversity gain over one antenna depends on the correlation between the antenna ports, their average gains and the environment in which the antennas operate. This environment includes the head of the operator apart from the general multipath environment. In this paper we first discuss the development of a single antenna and later the performance of multiple antennas. The analysis is based on finite-difference time-domain (FDTD) analysis of the antennas including the head, as well as measurements of angular information in the environment