An LTCC Interference Cancellation Device for Closely Spaced Antennas Decoupling

A compact interference cancellation device (ICD) offering a great decoupling for a pair of closely overlapped antennas and enhancing the throughput of the multi-input-multi-output (MIMO) system is proposed. The device is implemented using semi-lumped components with a compact size of 1.6 mm
$\times \,\, 0.8$
mm
$\times \,\, 0.6$
mm with the help of the low temperature co-fired ceramics multilayer fabrication technology. The proposed topology is applied to enhance the overall data throughput of a MIMO system with two overlapped antennas sharing a reduced clearance region. A MIMO antenna system consisting of two conventional coupled antennas locating at the same plane, and its counterpart containing two overlapped antennas integrated with the ICD chip are fully investigated. The experimental results demonstrate that around 10% overall throughput improvement of the MIMO system is obtained across the 2.4 GHz band while the ground clearance area of the antennas has been shrunk by 50%. It is also proved that the presented ICD device is a good candidate in applications of mobile terminals and wireless communication devices with very compact volumes.