Design of High Isolation Terminal Multiple Antennas Based on Characteristic Mode Analysis

Two Inverted-F Antennas (IFA) with high isolation is proposed based on characteristic mode analysis (CMA). By manipulating the resonance frequencies and mode weight coefficients (MWC) of two specific modes, both can be simultaneously excited. This ensures the creation of a current null zone at the opposite port when feeding a single port, effectively achieving decoupling. The proposed antenna operates within the range of 1.89-1.93GHz, exhibiting in-band isolation improvement from 9dB to exceeding 20dB. At the resonant frequency of 1.91GHz, the isolation reaches a maximum of 25dB.