IEEE TRANSACTIONS ON ANTENNAS AND PROPAGATION, vol. 57, no. 1, page. 283 - 286, 2009-01
MICROWAVE AND OPTICAL TECHNOLOGY LETTERS, vol. 51, no. 6, page. 1413 - 1416, 2009-06
IEEE ANTENNAS AND WIRELESS PROPAGATION LETTERS, vol. 8, page. 712 - 715, 2009-01