Abstract
A knowledge of low frequency (L.F) noise in FET's, HBT's and others related devices is essential in designing oscillators, multipliers, mixers and broadband amplifiers. Physical origins and assessment techniques ofthis noise are addressed A lot of L.F noise measurements on commercial and research devices either performed in our laboratory or picked up from literature are presented and are intended to give the state of the art of today available performance. Finally design rules for reducing the impact of L.F noise on microwave circuits are suggested.