A Cross-Band Decoupling Technique Based on Current Regulation

This paper proposes a method to reduce the cross-band coupling based on the frequency doubling or approximate frequency doubling case. When the high and low frequency bands exhibit an integer multiple relationship, the coupling current path length on the high frequency antenna when the low frequency antenna operates is about one-fourth of the waveguide wavelength of the electromagnetic wave in the low frequency band, which shows the monopole characteristic and makes the cross-band coupling higher. In this paper, by regulating the coupling current on the high-frequency antenna, carving a slot on the high-frequency antenna balun, bending the current, making the resonance frequency move to the lower frequencies, avoiding the low-frequency band so as to realize the cross-band decoupling, and finally reducing the cross-band coupling between the antennas from -10.3dB to -22dB.