A High-Pass Antenna Interference Cancellation Chip for Mutual Coupling Reduction of Antennas in Contiguous Frequency Bands

In this paper, an antenna interference cancellation chip (AICC) with a high-pass response is proposed to mitigate the mutual coupling of two antennas resonating in contiguous frequency bands. Using the most up-to-date low temperature co-fired ceramic (LTCC) technology, the chip only occupies a compact volume of 1.6 × 0.8 × 0.6 mm
³
. Two external tuning capacitors and two shunt inductors together with the LTCC AICC device which are in shunt with two coupled antennas, are able to improve the antenna isolation near band-edge by more than 15 dB without sacrificing antenna performance in its useful resonating bands. The high-pass property of the AICC device prevents the decoupling design near 2.4GHz affecting the successful operation of GPS at 1.575 GHz. The superiority of the proposed method is verified with active measurement of a Mi-Fi (mobile Wi-Fi) device in Wi-Fi hotspot mode using the AICC device. The proposed AICC device and corresponding decoupling method with the device can find plenty of applications in long-term-evolution and future 5G wireless platforms.