An Integrated Antenna Interference Cancellation Chip With Frequency Rejection Characteristic for MIMO Systems

An integrated antenna interference cancellation chip (AIC^2) reducing the inevitable interference between two closely located dual-band multiple-input-multiple-output (MIMO) antennas is introduced. The chip is realized by semilumped components in a volume of 1.6 × 0.8 × 0.6 mm
³
using multilayer low temperature co-fired ceramic technology. The proposed topology is applied to two MIMO antennas for IEEE 802.11 n/ac dual-band application. One demonstration board containing only antennas that are strongly coupled and its counter-part containing an integrated AIC^2 chip are designed, fabricated, and measured. It is shown that 10-dB isolation improvement can be achieved within the 2.4-GHz band while the performance at the 5.8-GHz band is well maintained simultaneously. The presented AIC^2 device is suitable for use in mobile Wi-Fi hotspots, smartphones, and wearable devices.