Research Project Title
Investigations into Approaches for Antenna Tunability and Compatibility

Principal Investigators
Jennifer T. Bernhard

Unit # 33
Project Overview

Manufacturers of next-generation wireless communication devices are moving toward the development of multifunction systems – ones that provide users with options of connecting to different kinds of wireless services for different purposes at different times. One method to achieve this functionality in portable wireless devices is to make the antenna tunable over discrete and/or continuous frequency bands.

 

This project has two objectives.  The first objective is to investigate methods to achieve antenna tunability over discrete and/or continuous frequency bands using solid-state devices that are compatible with existing portable device technology. Antenna frequency tunability has been demonstrated using a number of different techniques that use varactors, diodes, field effect transistors, and, more recently, RF MEMS and optical switches. Switching over closely spaced bands may be easily achieved using any of these techniques, while more broadly spaced bands pose more difficulties since large changes in operating frequency may also be accompanied by large changes in radiation characteristics. In this research, we will explore current and emerging techniques for achieving antenna tunability with solid-state devices that are compatible with commercial wireless devices and packages. Particular emphasis will be placed on design methodologies that optimize the interface between various antenna structures and the inherent limitations of the switching device.

 

The second objective is the investigation of methods for antenna and package design that help to achieve compatibility/isolation with co-located or nearby communication systems. We will concentrate on manipulation of antenna near-field properties to allow compatibility with hearing aids. Our approach to this research will differ from that of others in this field by taking packaging and usage scenarios into account from the outset. Our experience has shown us that a wireless system’s performance is largely dependent on how well the antenna works in a particular environment (including package design and composition, circuit board and ground plane structure, and anticipated user proximity). If the antennas are designed with no consideration for any of these factors, the antenna will likely not perform optimally and system performance will suffer. Our goal is to provide design guidelines and procedures that deliver exceptional antenna performance in practical, feasible forms for commercial wireless packages.