Switchable graded index microwave metamaterial lens design using pneumatic actuation

We propose the design of graded index metamaterial lens using pneumatic actuation for switching between focusing and non focusing states and operating at 9 GHz. Graded refractive index is engineered by using split ring resonators of different widths. Choice of electrical resonators allows planar design and significantly reduced thickness of the lens. Switching between focusing and non focusing states is based on shortening the gaps in split ring resonators with pneumatically actuated metal patches. This leads to the disappearance of the resonant response of split rings and flattening of phase difference between the elements across the lens. The concept is demonstrated by fabrication and measurement of two versions of the lens representing focusing and non focusing states.