Reconfigurable Antennas Enabled by Compliant Mechanisms

Today’s ever-expanding need for wide- and multi-band communications systems places considerable burdens on available apertures. Many systems now operate over multiple bands simultaneously while requiring tunable behaviors such as beam forming and steering, nulling, polarization modulation, amongst others. While phased array systems have largely been successful in realizing many of these phenomena, they are ultimately limited in applications where extreme reconfigurability is needed to achieve a targeted performance (e.g., mechanical deformation) and when dealing with high power microwaves (HPMs). To this end, researchers have augmented classical antenna systems with metamaterials to enhance their intrinsic properties and introduce new pathways to tunability. However, careful considerations need to be taken when designing metamaterial antennas for HPM applications due to their tendency to strongly localize incident fields [1]. Therefore, reconfigurable antenna technologies that can enable unprecedented tunability, mechanical ruggedness, and HPM compatibility are extremely desirable. To this end, compliant mechanisms [2] are an attractive pathway for meeting these challenges. Compliant mechanisms are mechanical structures that realize complex mechanical movements with simple actuations and without gears, pulleys, or hinges, but rather through intelligent design and exploitation of their intrinsic material properties. Compliant mechanisms are often fabricated through additive manufacturing which further lends themselves to rapid prototyping and integration into antenna systems as dielectric support structures or metalized components. An overview of compliant mechanisms for next generation reconfigurable electromagnetic devices was presented in [3]. Figure 1 presents a visual synopsis of many of the desirable properties of tailored compliant mechanisms for reconfigurable antenna design. This presentation will summarize the current state of the art in compliant mechanism augmented antenna design and showcase multiple fabricated and measured prototype devices.