ELECTRONICS LETTERS, vol. 48, no. 15, page. 935 - 954, 2012-07-19
ELECTRONICS LETTERS, vol. 45, no. 22, page. 1121 - 1122, 2009-10-22
IEEE Microwave and Wireless Components Letters, vol. 22, no. 7, page. 363 - 365, 2012-07