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A. Pérennec-was-born-in-quimper and F. , He received the Ph.D degree in electronics from the (France) in 1988. Presently, he is assistant professor in the Lab-STICC (UMR CNRS 3192) His research interests are in the active and passive device microwave area and include amplifier design (low-noise and broad-band), and filters. He also works on optoelectronic and microwave periodic devices. Currently, his main research interests concern circuits with negative group delay, 1960.