In this letter, we present a wideband decoupling technique for closely located SICL-Fed dipole antennas operating at ka-band. Based on split-loop resonator, a kind of novel multi-layer split-loop is proposed. It located in the end of dipole arms. With a proper size, the proposed decoupling structure can reduce the mutual coupling between two adjacent elements. The antennas consist of three Yagi-Uda dipole antennas. They are individually excited, and therefore can receive and transmit different signals separately. The simulated results show a wide impedance bandwidth of lager than 46 % (26.5-42.2GHz), a high port-to-port isolation (better than 25 dB) within the operating frequency bandwidth, and a good radiation pattern. It shows the interested antennas has a good application prospect in MIMO antenna array.