With the rapid development of wireless communication systems, there is a demand for communication devices that provide multiple services, over a wide range of frequencies, simultaneously but remaining compact in volume. There are many challenges in achieving this goal and in this thesis the focus is on those relating to the design of the reconfigurable antennas which allow the antenna to change its shape to service different systems at different times and therefore make efficient use of the volume available. The design of reconfigurable antennas is more intricate because of the inclusion of extra components which have to be designed, modeled and fabricated simultaneously with the main structure.

This research work provides a comprehensive design workflow, optimization and impl...[ Read more ]

With the rapid development of wireless communication systems, there is a demand for communication devices that provide multiple services, over a wide range of frequencies, simultaneously but remaining compact in volume. There are many challenges in achieving this goal and in this thesis the focus is on those relating to the design of the reconfigurable antennas which allow the antenna to change its shape to service different systems at different times and therefore make efficient use of the volume available. The design of reconfigurable antennas is more intricate because of the inclusion of extra components which have to be designed, modeled and fabricated simultaneously with the main structure.

This research work provides a comprehensive design workflow, optimization and implementation of reconfigurable antennas. The first part focuses on pixel antenna designs, which are the foundation of reconfigurable designs. The optimization problems are simplified by an internal multi-port method which can be solved efficiently by genetic algorithms. We also describe two deterministic approaches referred to as mixed integer programming and successive Boolean optimization. In the second part, we describe the optimization for frequency reconfigurable pixel antennas, which utilizes a multi-objective function solved by a multi-objective genetic algorithm. Minimization of the number of switches in the design is also attempted. The effects of the RF MEMS switches as well as the control feed lines on the antenna performance are also addressed. In the third part, we introduce the reconfigurable pixel slot antenna. We also discuss some techniques for the reduction of mutual coupling between closely-packed slot antennas which can be applied in the design of reconfigurable MIMO antennas. Various examples are presented in this thesis to demonstrate the proposed methods.