Compact Dual-Polarized UWB Quasi-Self-Complementary MIMO/Diversity Antenna With Band-Rejection Capability

A novel compact ultrawideband (UWB) multiple-input-multiple-output (MIMO) antenna system with dual polarization and band-rejection capabilities is proposed. The proposed MIMO antenna system consists of two quasi-self-complementary (QSC) antenna elements. The elements are arranged orthogonally and fed perpendicularly to obtain polarization diversity. High isolation can be achieved without additional decoupling structure owing to the inherent advantage of the self-complementary structure. Notched band at WLAN system can be realized by etching a bent slit in each of the radiating elements. Moreover, a four-element MIMO system is also proposed and investigated to fully reveal its potential use. Diversity performance in terms of envelope correlation coefficient (ECC) and the mean effective gain (MEG) ratio are studied. Measured results show that the proposed antenna has a wide bandwidth ranging from 3 to 12 GHz with band rejection at WLAN system and high port isolation (S
₁₂
≤ -20 dB at most of the band), which demonstrate the proposed MIMO/diversity antenna system can be a good candidate for UWB applications.