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IEEE Transactions on Antennas and Propagation
Volume 47 Number 5, May 1999

Table of Contents for this issue

Complete paper in PDF format

Performance of Shorted Microstrip Patch Antennas for Mobile Communications Handsets at 1800 MHz

Jack T. Rowley, Member, IEEE, and Rod B. Waterhouse, Member, IEEE

Page 815.

Abstract:

We have investigated the application of two different types of novel shorted-patch antennas for mobile communications handsets at 1800 MHz. A single shorted-patch and a stacked shorted-patch antenna offering improved bandwidth are compared with data for a \lambda/4 monopole. The finite-difference time-domain (FDTD) technique was used to calculate antenna characteristics such as impedance and radiation patterns for two cases: on a handset and on a handset near a (2.5-mm voxel) heterogeneous head model in an actual position of phone use. We also obtained specific absorption rate (SAR) distributions and calculated the spatial peak 1-g SAR values. In addition, the effect on SAR and antenna characteristics of including a block model of the hand was assessed. Similar performance is achieved from the single or stacked shorted-patch antenna with the latter providing greater bandwidth, 8.2% versus 9.4% with the head and hand included. Both antennas reduce the 1-g spatial peak SAR value in the head by 70% relative to the monopole. The presence of the hand reduces the efficiency of all three antenna types by approximately 10%.

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