Design of compact RF choke for suppressing ground edge current in LTE mobile application

A radio frequency choke (RFC) is proposed for suppressing ground edge currents which lead to a degradation of antenna performance in a MIMO communication system. The proposed RFC is designed compactly in size of 14.88 mm × 10.98 mm, in order to implement compatibly in a high-integrated RF circuit board. For determining the isolation performance of proposed RFC, the experiments consist of a 50 Ω transmission line mounted on the proposed RFC, as well as the transmission coefficient of an electromagnetic wave passing through the line is observed. The isolation can be enhanced by implementing the proposed RFC structure in the MIMO antenna configuration. The achieved envelope correlation coefficient is less than 0.14 in LTE 2300 band and it can be regarded as a reliable result for improving the diversity performance in MIMO antenna system.