<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN"> <html> <head> <meta http-equiv="content-type" content="text/html; charset=windows-1252"/> <title></title> <meta name="generator" content="LibreOffice 5.0.3.2 (Windows)"/> <meta name="created" content="00:00:00"/> <meta name="changed" content="2016-01-16T13:32:32.474000000"/> <style type="text/css"> @page { margin: 2cm } p { margin-bottom: 0.25cm; line-height: 120% } a:link { so-language: zxx } </style> </head> <body lang="fr-FR" dir="ltr"> <p style="margin-bottom: 0cm; font-style: normal; font-weight: normal; line-height: 100%"> <font face="Times New Roman, serif"><font size="6" style="font-size: 22pt"><b>Z</b><sub><b>in</b></sub> desired input impedance in Ω</font></font></p> <p style="margin-bottom: 0cm; font-style: normal; font-weight: normal; line-height: 100%"> <font face="Times New Roman, serif"><font size="6" style="font-size: 22pt"><b>Z</b><sub><b>out</b></sub><sub> </sub> desired output impedance in Ω</font></font></p> <p style="margin-bottom: 0cm; font-style: normal; font-weight: normal; line-height: 100%"> <font face="Times New Roman, serif"><font size="6" style="font-size: 22pt">a attenuation in dB</font></font></p> <p style="margin-bottom: 0cm; font-style: normal; font-weight: normal; line-height: 100%"> <font face="Times New Roman, serif"><font size="6" style="font-size: 22pt">L = 10<sup>a/10</sup> (the loss)</font></font></p> <p style="margin-bottom: 0cm; font-style: normal; font-weight: normal; line-height: 100%"> <font face="Times New Roman, serif"><font size="6" style="font-size: 22pt">A = (L + 1)/(L − 1)</font></font></p> <p style="margin-bottom: 0cm; font-style: normal; font-weight: normal; line-height: 100%"> <br/> </p> <p style="margin-bottom: 0cm; font-style: normal; line-height: 100%"><font face="Times New Roman, serif"><font size="6" style="font-size: 28pt"><b>Pi attenuator</b></font></font></p> <p style="margin-bottom: 0cm; line-height: 100%"><font face="Times New Roman, serif"><font size="6" style="font-size: 28pt"><i><b>R2 = (L − 1)/2 * √ ((Z<sub>in</sub> * Z<sub>out</sub>)/L)</b></i></font></font></p> <p style="margin-bottom: 0cm; line-height: 100%"><font face="Times New Roman, serif"><font size="6" style="font-size: 28pt"><i><b>R1 = 1/( A/Z<sub>in</sub> − 1/R2)</b></i></font></font></p> <p style="margin-bottom: 0cm; line-height: 100%"><font face="Times New Roman, serif"><font size="6" style="font-size: 28pt"><i><b>R3 = 1/ (A/Z<sub>out</sub> − 1/R2)</b></i></font></font></p> </body> </html>