Yeong-Jar Chang, Chung Len Lee, Jwu E Chen+ and Chauchin Su++
Department of Electronics Engineering & INstitute of Electronics
National Chaio Tung University
Hsinchu, Taiwan 300, R.O.C.
+Department of Electrical Engineering
Chung-Hua University
Hsinchu, Taiwan 300, R.O.C.
++Department of Electrical Engineering
National Central University
Chungli, Taiwan 320, R.O.C.