Abstract: In this paper, a substrate integrated omnidirectional filtenna multi-input multi-output (MIMO) array at Ku band for frequency division multiplexing (FDD) system is presented.The filtenna is seamless and incorporate design of radio frequency (RF) filter and antenna for reducing losses introduced by the transmission between RF filters and radiation elements and suppressing singles of adjacent frequencies. After simulated, fabricated, measured and compared, it is concluded that performances of single filtenna have nearly no change within the working frequency while the out of band signal is effectively filtered.Filtennas working at 13.6GHz band and 14.4GHz band with 100 MHz bandwidth have excellent isolation performance and are suitable for transmitting and receiving channels in FDD system. The characteristic of single filtenna in MIMO array keeps omnidirectional radiation pattern.