Reduction of dual-band mutual couplings between two antennas by dual-band single-negative epsilon metamaterials

In this research, an efficient method using a dual-band ENG (ε-Negative) metamaterial is proposed to reduce the dual-band mutual couplings between two monopole antennas for multiple-input multiple-output application. The present technique can effectively reduce the mutual coupling for two Worldwide Interoperability for Microwave Access 2.6 GHz/3.5 GHz bands. The dual-band isolations are improved by over 10 dB level, according to the introduction of present isolation technique, and the two monopole antennas can reach below 20 dB mutual couplings at the two working bands, which are verified by measurement results.