SIW resonator humidity sensor based on layered black phosphorus

A passive microwave substrate-integrated waveguide (SIW) resonator humidity sensor using black phosphorus (BP) as sensitive layers has been presented. The proposed structure consists of an SIW cavity resonator operating at S-band and a folded sensing slot opened on the top plane. The humidity sensing performances of the proposed sensor were tested in the relative humidity range of 11–97%. Compared with an SIW resonator without BP sensitive layers, the sensitivity of the proposed SIW sensor with BP nanosheets significantly increased about 40 times.