Low cost, dual linearly polarised microstrip patch array

The design and experiments of a novel dual linearly polarised (LP) microstrip antenna array with a high isolation and low cross-polarisation levels are presented. The theoretical analysis is based on the finite-difference time-domain method and the multiport network model. The multifeed technique and the diagonal feeding are combined to realise the dual-polarised antenna elements. A single antenna element is designed and the experimental results show a good isolation between two polarisation ports. The dual LP elements are sequentially rotated to form the microstrip antenna array. A four-element dual LP array is also designed at 6.6 GHz and measured. Both theoretical and experimental results are presented and compared. The proposed array uses a single-layer structure so it is easy to fabricate and the cost is very low. It is also easy to extend the principle of present array to large-scale dual LP arrays and those of multilayered structures.