分立元件设计的低噪声前置放大器实用电路第 28 卷　第 4 期 2005 年 12 月 　　　　　　 　 电　子　器　件 Ch inese Jou rna l of E lect ron D evices 　 V o l128 N o. 4 D ec. 2005 Appl ied C ircu it of L ower - No ise Pream pl if ier Com posed by Una ttached Com ponen ts GUO Y u , L U Y ong 2k ang , CH EN B o ( Institu te of Geop hy sics&Geom a tics, C h ina U n iversity of Geosciences, W uhan 430074, C h ina ) Abstract: A cco rd ing to series2 w ound am p lifiers and no ise theo ry , an app lied circu it of low 2no ise . T he resu lt show s tha t the circu it ha s low er no ise p ream p lifier is designed u sing una t tached com ponen t s vo ltage than the low 2no ise op era t iona l am p lifiers ex isted in the p resen t m a rket. p ream p lifier fo r the signa l genera to r w ith low innet resistance. Keywords: t ran sisto r; no ise ana ly sis; p……