Broadband Decoupling Patch Antenna Array for Millimeter-Wave Full-Duplex Applications

This letter describes a low-profile decoupling method aimed at reducing the mutual coupling between millimeter-wave (mm-wave) patch antenna arrays. The decoupling structure consists of tightly packed coupled transmission lines and metal vias, which are symmetrically arranged on the four diagonals of the patch antenna. This compact design can effectively meet the coupling challenge when the center of the antenna elements is only half wavelength without increasing the profile height of the antenna. Through processing and testing of a 1×2 antenna array, it is verified that the decoupling bandwidth of the proposed decoupling structure is 9.84% from 23.86 to 26.16 GHz, where the coupling is less than -40 dB, and the reflection coefficient is below -10 dB. Within the decoupling bandwidth, the simulated results show that the total efficiency is greater than 86.4% with a peak value of 90.6%. This method demonstrates excellent scalability in one-dimensional antenna arrays and holds significant potential for applications in full-duplex communication systems.