Abstract:Multi functional microwave devices play an important role in modern communication systems because they can achieve large capacity function integration in small sized devices. However, multifunctional devices often exhibits serious channel crosstalk due to the high integration, which significantly reduces the device efficiency. Here, a frequency multiplexing method with low channel crosstalk is proposed. A double Cshaped slot resonator and a double C shaped metal resonator are utilized in a complementary form on two dielectric boards for realizing a hybrid meta atom with double operation modes. The high Q value being achieved in hybrid resonator, the phase can be controlled independently at two operation bands with low frequency ratio. To verify the concept and explore possible applications, a bifunctional metasurface with two distinct functions are designed at f1=9.2 GHz and f2=11.2 GHz. The numerical results are in good agreement with the experimental ones, indicating a focused OAM beam with mode number l=3 at f1 and a zero order Bessel beam at f2. Compared with the previously reported wavelength multiplexing devices, the frequency ratio of dual operation modes here is only 1.2, and the efficiency is measured as 86.1% and 93% respectively. The wavelength multiplexing method with low frequency ratio and low channel crosstalk provides an effective avenue in high capacity integrated function application.