An Antenna Decoupling Method by Using Frequency Selective Surface

A simple and efficient method to reduce the mutual coupling between two closely spaced (about 0.4 λ) antennas is proposed in this paper. By inserting a frequency selective surface (FSS) which can transform the vertical and horizontal polarized incident waves into horizontal and vertical polarized transmitted waves, the isolation of two parallel dipoles can get enhanced greatly. The simulation results indicate that a range of 4-26dB reduction in mutual coupling between the two dipoles can be obtained at 3.8-4.2GHz when the FSS cell is inserted between them, which is a satisfactory level. This decoupling method can be applied to the array of three-dimensional antenna structure because of its advantage of availability.