Advanced wireless product design from components to smart antenna systems

The ultimate objective of this talk is to propose research and development activities toward the achievement of the more advanced electromagnetic design capabilities required to address future industrial and consumer electronics products, particularly wireless products. In order to elucidate the need for better design capabilities, the talk starts with the description of some advanced antenna concepts for wireless handsets. The examples are chosen so that they span the key fundamental electromagnetic principles from electrically small to Multiple Input Multiple Output (MIMO) antennas. Recently, the number of papers on "antenna miniaturization" has dramatically increased. The performance trade-offs involved with miniaturization of antennas and key principles for robust comparisons are briefly reviewed. Then, a new antenna design concept, the "exotenna" is described. Miniaturization design concepts for consumer electronics try to minimize the antenna volume. This miniaturization often causes highly concentrated currents on the antenna and/or induced currents on the components and subsystems next to the antenna. Very careful design with "packaging" principles has to be applied for the successful implementation of such small antennas in wireless products. Typically, if one wants to capture and predict the antenna behaviour well, CAD tools capable of dealing with geometric complexity are required. The exotenna, on the other hand, tries to achieve the maximum possible volume in the product by being distributed over its housing. Even though this often brings the antenna in contact with lossy mechanisms, detuning it and degrading its radiation efficiency, a distributed antenna system over the largest possible surface achieves remarkably good performance. The exotenna points toward engineering co-design and multidisciplinary optimization more than ever before. Moreover, in MIMO systems, the antenna is used to provide additional design degrees of freedom to accommodate more advanced communications systems. Some of the peculiarities of MIMO antenna performance are described, especially as they relate to the propagation environments that they operate in. System performance metrics are typically more robust when they pertain to higher layer attributes such as Bit Error Rate. Yet, the mapping of those metrics down to the antenna performance is not as straightforward, or unique. MIMO systems point to the direction of cross-layer design and optimization as never before. Now that the challenges of future antenna design have been clarified, the talk continues with a proposed framework for Multidisciplinary Optimization and Cross-Layered Design and Modeling. The framework outlines a structure and requirements for the participating software tools. Additionally, requirements on electromagnetic solvers are described so that they can handle these new complex tasks. In particular, the exciting new field of domain decomposition is mentioned and extensions that could simultaneously address geometric complexity and full wave solution of large antenna arrays encountered in MIMO systems.