September 1966 to September 1968-Research assistant, design Pico second waveform measurements at UCLA.

September 1968 to June 1970- Teaching Assistant of Electronic Lab, and work for Ph. D. thesis.

Sept. 1970 to Jan. 1971 – Assistant Prof. at Higher Institute of Telecommunication and Univ. of Tehran – Iran.

Jan. 1971 to June 1976 – Assistant Prof, and chairman of E.E. dept. at IUST.

June 1976 to June 1977- –Assistant Prof. One year sabbatical leave at Hughes Aircraft Company, aerospace division, Canoga Park, California, U.S.A.

June 1977 to June 1980 – Chairman of E.E. dept. and vice president of Research and development of IUST.

June 1980 to June 1984- –Assistant Prof. and manager of some research projects. June 1984 to present – Prof of. IUST.