IEICE TRANSACTIONS ON ELECTRONICS, vol. E82C, no. 6, page. 1018 - 1024, 1999-06
IEEE TRANSACTIONS ON MICROWAVE THEORY AND TECHNIQUES, vol. 45, no. 12, page. 2065 - 2072, 1997-12
MICROWAVE AND OPTICAL TECHNOLOGY LETTERS, vol. 16, no. 1, page. 38 - 41, 1997-09