An efficient broadband metasurface design for smart health care and future communication applications

• It offers a new multi-functional reflective polarizer metasurface. • It offers a high angle stability in polarization conversion. • It offers linear-to-circular conversions in five frequency region in Ku, U bands. • It offers linear-to-linear conversions in a huge broadband covering Ku, K, Ka, U bands. • It offers a high PCR efficiency in a huge broadband compared to the literature. We propose a broadband metasurface consisting of a novel compact resonator to achieve linear polarization conversion in reflection mode. This compact resonator is designed on Roger 5880 substrate, measuring 1.575 mm in thickness, and possessing a loss tangent of 0.004. This structure is also upheld by a metal ground. The described unit cell effectively sends back incoming waves by converting 90 0 across a wide range of frequencies. This unit cell presents an efficiency exceeding 90 % for polarization conversion in the following frequency regimes: 12.2–41.5 GHz for normal incident waves. At the same time, this design includes polarization conversion with 90 % efficiency in broadband from 12.5 GHz to 30.6 GHz for angularly polarized waves up to 30 0 . Behind this broadband polarization transformation lies the concept of surface current distribution and a high impedance surface. Given the broad-spectrum coverage and high-efficiency polarization conversion capabilities, our proposal holds significant potential for a wide range of applications.