Experimental verification of the reduction of coupling between dipole antennas by using a woodpile substrate

In this paper, the mutual coupling between dipole antennas placed on top of a woodpile structure is experimentally investigated. The coupling between dipoles backed by a woodpile substrate is compared with that obtained when the dipole antennas are placed on a dielectric substrate and when they radiate into free space. On average, between 2 and 7 dB reduction of the mutual coupling is achieved with respect to the dielectric substrate case when the woodpile substrate is used. The free space coupling is also reduced in the H-plane configuration case. However, the E-plane coupling slightly increases due to modification of the radiation pattern. Imaging array applications could potentially benefit from the use of EBG substrates due to the improved isolation between pixels.