A coupled resonator decoupling network for four-element antenna arrays

This paper proposes an effective solution to reduce various types of coupling between four tightly placed antenna elements. To validate the decoupling method, four-element monopole antennas are used as an example for design. The results indicate that the four-port decoupling network can suppress various types of coupling below -20 dB in the 3.45-3.66 GHz frequency band when the reflection coefficient is below -10 dB. Meanwhile, compared with the antennas without decoupling measures, the total efficiency of decoupling antennas is improved and the envelope correlation coefficient is significantly reduced in the frequency band of interest.