Isolation technique using the A/4 Stub RF Choke for the mobile MIMO system

Abstract

The isolation technique using the λ /4 Stub RF Choke is proposed in this paper. The isolation technique between two antenna elements is important in order to prevent the edge current cause degradation of the antenna performances. The Radio Frequency choke (RFC) is placed in the middle of two conventional inverted-F antenna elements to improve the isolation between the two antennas. The shape of λ /4 Stub which is connected with the top of the ground plane is changed to reduce its physical size by bending and being burrowed into the ground plane. The MIMO antenna elements are well matched in the range of LTE 2300 (2300 ~ 2400 MHz) band and have a return loss under -6 dB (VSWR <; 3) also, the isolation is lower than -20 dB at the center frequency. The Envelope Correlation Coefficient (ECC) value is under 0.2 which shows that good isolation is achieved.