Multifunctional Frequency Selective Absorber Enabling FR1 and FR2 5G OTA Tests in a Hybrid Reverberation Chamber.

Due to the special advantages of the reverberation chamber (RC), it has been recognized as a standardized over-the-air (OTA) testing methodology by the cellular telecommunications industry association (CTIA). Currently, OTA tests of the fifth-generation (5G) wireless terminals are usually performed in different testing environments, e.g., in an RC for fast isotropic tests in the sub-6 GHz frequency band, and in an anechoic chamber for directional tests in the millimeter-wave (mm-wave) frequency band, which are inconvenient and costly. In this work, two multifunctional frequency selective absorbers (FSAs) are designed to realize absorption in the 5G mm-waveband and reflection/transmission in the sub-6 GHz band. By loading the FSAs to the RC, an integrated testing environment for 5G terminals can be established. Namely, a quasi-anechoic environment in the mm-waveband and a reverberation environment in the sub-6 GHz band can be simultaneously achieved in the RC loaded with the proposed FSAs. Experimental and simulated results are presented to demonstrate the effectiveness of the proposed scheme.