Antenna Analysis, Design and Measurement Techniques

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The Canadian wireless industry continues to be innovative at both the system and equipment level, provides essential services to Canadians, and employs thousands. Wireless communications pervades everything, and if anything is wireless (as opposed to wired) antennas are required. The objective of the proposed research is to advance the tools for the analysis, design and measurement of improved antennas for the many emerging wireless applications. A theme running through the proposal is that of letting the electromagnetics directly guide us as to the shape of the antennas needed to achieve the performance we desire. In other words, the use of shape synthesis in antenna design. One antenna type needed in wireless applications is that which must fit in the crammed environment of portable devices (such as handheld phones and sensors, generically referred to as platforms) and so has been increasingly difficult to design. Several antennas may be needed on a single platform, each of whose performance is influenced by the others and the platform. In the case of phones, such antennas now need beams that can be electronically steered. The space allotted to a particular antenna may prevent conventional designs from being used. New shape synthesis methods will facilitate such designs. Wireless systems under development will use smaller cells (zones in which the system base-station communicates with a user) that utilize millimetre-wave bands, as high as 90 GHz in the future, due to insatiable capacity demands. The high propagation losses at these frequencies will be exploited to keep cells from interfering with each other. But this means that another class of antenna, namely higher directivity antennas (narrow beams), are also needed as part of the system. To satisfy aggressive cost constraints the antennas must use printed (including 3D) technology. At millimetre-wave frequencies the signal losses in the beamforming circuits of conventional high directivity printed arrays are a limiting factor. Shape synthesis offers the promise of synthesizing alternative higher directivity conducting and dielectric antennas with decreased losses, with desirable physically low profiles. The proposed research will advance our work on antenna shape synthesis by significantly extending the range of applications to which our existing shape synthesis can be applied. We will achieve this by implementing and developing the completely new "subtractive/additive shape synthesis" approach we have recently devised; it can overcome many of the obstacles and limitations experienced by current shape synthesis methods. We will also infuse more computational intelligence into this new process, and our existing shaping algorithms, to increase the computational speed at which such shape synthesis can be performed. This is essential if shape synthesis is to become a well-used design pathway that is complementary to more conventional design methods in wireless engineering practice.