IEEE TRANSACTIONS ON MICROWAVE THEORY AND TECHNIQUES, vol. 45, no. 8, page. 1252 - 1255, 1997-08
ELECTRONICS LETTERS, vol. 32, no. 20, page. 1928 - 1929, 1996-09-26
MICROWAVE AND OPTICAL TECHNOLOGY LETTERS, vol. 6, no. 2, page. 98 - 101, 1993-02
MICROWAVE AND OPTICAL TECHNOLOGY LETTERS, vol. 5, no. 7, page. 313 - 315, 1992-06-20