  Metasurfaces (MSs) have been utilized to manipulate different properties of
electromagnetic waves. By combining local control over the wave amplitude,
phase, and polarization into a single tunable structure, a multi-functional and
reconfigurable metasurface can be realized, capable of full control over
incident radiation. Here, we experimentally validate a multi-functional
metasurface architecture for the microwave regime, where in principle variable
loads are connected behind the backplane to reconfigurably shape the complex
surface impedance. As a proof-of-concept step, we fabricate several metasurface
instances with static loads in different configurations (surface mount
capacitors and resistors of different values in different connection
topologies) to validate the approach and showcase the different achievable
functionalities. Specifically, we show perfect absorption for oblique incidence
(both polarizations), broadband linear polarization conversion, and beam
splitting, demonstrating control over the amplitude, polarization state, and
wavefront, respectively. Measurements are performed in the 4-18 GHz range
inside an anechoic chamber and show good agreement with
theoretically-anticipated results. Our results clearly demonstrate the
practical potential of the proposed architecture for reconfigurable
electromagnetic wave manipulation.
