LNA + mixer simulation ?

Dear all :

I work on LNA+Mixer simulation of FM band. Now I have some question .

1.Does FM is wide band ? I match the input stage, I found the S11 in the smaith chat is very high range, so that the Gain in not flaten. Like 72M is 13dB 90M is 25dB, 108M is 17dB. How do I to solve the problem ?

2. LNA + mixer Gain simulation. I can simulate the LNA , Mixer Gain, standalone. But I casecad the LNA+Mixer , I check the Conversion Gan, It can't work ? What is the Gain , See the S21 or other method . Thanks

u need to make the S parameter simulation detect frequency translation
, and try to use HB simulation to get the gain

about the gain flatness , i think u should use wide band matching circuit and also try to make the mixer gain flat alone


khouly

You should use simulation other than sp ,coz the frequency is to low,beside the input S11 is impossible well matched at this frequency.
maybe ac simulation is suitable

Dear All :

So that in the 72M ~ 108M , It is hard to matching for this band or there are still have good mwthod for matching , Thanks

u ca search for wide band matching techniques

khouly