Abstract:
Reconfigurable antennas present many advantages in terms of reconfiguring their operational frequency, radiation characteristics, or polarization. There are many types of reconfigurable antennas that can be reconfigured either electrically or mechanically. While electrically reconfigured antennas are highly popular, some applications depend on mechanical reconfiguration mechanisms for antenna operation agility. Designing a mechanically reconfigurable antenna by itself is challenging, however, reducing power consumption as well as size and volume is an ongoing challenge for many researchers.
In this thesis, a novel low power mechanically reconfigurable antenna based on Chladni patterns is presented. The design concept is based on the vibration of a thin plate covered with conductive powder that is in turn mounted on top of a circular microstrip. Vibrating the thin plate with various frequencies will distribute the conductive powder on top of the antenna in different Chladni patterns. Each Chladni pattern will reconfigure the antenna’s operational frequency. To maintain the shape of the powder during the operation of the antenna, a compressing mechanism is devised. To minimize the power consumption of the compression mechanism, Shape memory alloys (SMA) are used in conjunction with a ratchet mechanism to achieve compressing and uncompressing the conductive powder. The ratchet mechanism is designed to minimizes any effect on the antenna operation while being quick and flexible in its positioning. The compression mechanism serves to preserve the obtained Chladni pattern, regardless of the position or configuration of the antenna platform. Finally, the performance of an antenna prototype is assessed via simulation, and by fabricating a functional prototype.
