Johann Siegl, born on June 5, 1947, received the Ing.(grad.) degree from the Ingenieurschule Miinchen, Germany in 1970 and the Dipl.-Ing. degree from the Technical University Berlin in 1973, From 1973 to 1978, while at the Institute of High-Frequency Engineering, he was a Research and Teaching Assistant at the Technical University in Berlin. He has been engaged in investigations into the properties of slot lines and fin lines in the millimeter-wave freauencv ramze. In 1978 he received the Dr.–Ing. degree from the Technica~ Uni~ersit~ in Berlin. At the beginning of 1979 he joined the Communications Group at Siemens AG in Munich, his first assignment being the computeraided design of microwave integrated circuits. Since 1981 he has been involved in the development of digital transmission systems.