[求助] 怎样抑制晶振的多次谐波？？

gardener

在手机设计中，怎样抑制晶振的多次谐波？？请各位高手给与指点！！

wilsonchen

<P>Hi gardener,</P>
<P>Some ways for your reference,</P>
<P>1. Trace between TCXO/XTAL and IC not to narrow, and better to be 50ohm.</P>
<P>2. Use smaller capacitance AC coupling capacitor in this series path, and check its waveform on oscilloscope if it's sine/cosine wave like !</P>
<P>3. Make shorter as possible your trace between XTAL and RFIC.</P>
<P>4. Try to use different frequency plan of RFIC to avoid the harmonics of XTAL to affect your RX or TX.</P>
<P>Regards,</P>

<P align=right><FONT color=red>+5 RD币</FONT></P>

gardener

thanks, I will try!

BOBLUE

遇到过两种13M倍频干扰的问题，都是在传导下就已经体现出来的，可以从两个方面来检查，查找是否有屏蔽盖接地不良引起，另外可以通过调整TCXO输出端并联电容来降谐波干扰[em01][br]<p align=right><font color=red>+3 RD币</font></p>

gardener

<P>屏蔽盖影响的可能性不是很大，未加屏蔽和加屏蔽盖都进行测量过，已确定是由晶振本身引起，</P><P>期盼中！！！</P>