Questions about LNA output design

[xuebi]

Now I'm designing the output part of LNA and I found little literature focused the output design of LNA. The following are my questions:
1) The LNA will be connected to the next stage. How to include the next stage input impedance when I simulate LNA using SpectreRF?
2) I use the shunt peaking technique for output design. The gain will be gm*RL*Q. In the output part, C represents the whole capacitance including output capacitance of transistor, parasitics and next stage input capacitance. How can I decide the value of L and R?
Please help me. Thanks a lot!

 

[sreechoudhary]

hai

1. you will match inputof the second stage by increasing the outputport resistance and combining with the balun .

2.as per my knowledge no ned of considering capacitance.you will get the values of R, L by using simple RLC resonance circuit formulae.

regards

Added after 2 minutes:

could you explain me how u will get the inputmatching for VHF range

i had posted suggetions but i didnt get any reply from you

please send me the circuit if possible.


regards
sree

 

[xuebi]

Generally speaking, the input impedance of the next stage is very high, so I can not check the power gain or S21 of the previous stage (LNA). I can just check the voltage gain of the LNA. Then how can I design the output network of the LNA?

By the way, VHF band is for DAB or DMB applications.

 

[sreechoudhary]

Could you please send me the circuit.

thanks and regards