l.j.zheng
Junior Member level 1
hi,all.
Recently I designed a transmit branch,including:mixer+filter+driver 1+driver 2+
PA(use GaAS FET matched by cap and ind). Now comes a problem: when measure
the branch at the driver2's output,the LO leak and LO+2IF leak are both about -70dBc(the PA doesn't work). But when measure at PA's output the LO leak is about
55dBc and the LO+2IF leak is about 50dBc. The output of PA hasn't reached P1dB(that is: the linearity is still good),and the IM3 is also good. Then why the LO leak
and LO+2IF leak becomes so strong, it badly disturbs me for several days.
I wish to get help from you!
Best Regards
L.J.zheng
Recently I designed a transmit branch,including:mixer+filter+driver 1+driver 2+
PA(use GaAS FET matched by cap and ind). Now comes a problem: when measure
the branch at the driver2's output,the LO leak and LO+2IF leak are both about -70dBc(the PA doesn't work). But when measure at PA's output the LO leak is about
55dBc and the LO+2IF leak is about 50dBc. The output of PA hasn't reached P1dB(that is: the linearity is still good),and the IM3 is also good. Then why the LO leak
and LO+2IF leak becomes so strong, it badly disturbs me for several days.
I wish to get help from you!
Best Regards
L.J.zheng