PERFORMANCE ANALYSIS OF ANTENNAS FOR HAND-HELD TRANSCEIVERS USING FDTD

The design of antennas for hand-held communications devices depends on the implementation of simulation tools that can accurately model gene ral topologies. This work presents the analysis of small antennas moun ted on hand-held transceivers using the finite-difference time-domain (FDTD) method. The key features of the FDTD implementation are discuss ed, with particular emphasis placed upon modeling of the source region . The technique is used to predict the gain patterns and broad-band in put impedance behavior of monopole, planar inverted F, and loop antenn a elements mounted on the handset Effects of the conducting handset ch assis, the plastic casing around the device, and lumped elements integ rated into the antenna design are illustrated. Experimental results ar e provided to verify the accuracy of the computational methodology. Th e concept of antenna diversity is discussed, and key assumptions and e xpressions are provided that characterize the multipath fading fields. Several computational examples demonstrate the diversity performance of two receiving antennas on a single handset.