Need help on LNA topology

[xuebi]

Now I need design a LNA with its main specifications as following.

BW: 174-245MHz,
Gain: 20dB,
NF: 2dB
0.18 CMOS process.

It is a wideband LNA (Bandwidth~33%). The cascode architecture with source inductive degeneration is just suitable for narrowband. Moreover, the degeneration indutor will be too large at these frequencies and can not be made onchip.

Can anyone recommend me some proper LNA topology?

Thanks!

 

[leomecma]

I have saw many topic with title LNA, but I don't know what this means and do. Can you give a simple explain about it?

thanks,

leomecma

 

[No one]

Hello xuebi;
I think that you should see the microwave amplifier books, like the Gonzalez and/or Vendelin. Also read application notes published by companies like Agilent and Minicircuits. Also simulate your project by a microwave simulating software.

 

[xuebi]

LNA: Low Noise Amplifier.

 

[sunking]

https://www.edaboard.com/forums/96/

 

[sreechoudhary]

yes

you can do that one with inductive degeneration with offchip inductor

you will get wideband matching in 3 ways

1.by dequing the circuit

2.by adding extra pole at the input matching

3.by using varactor diode inplace of capacitor(this one may be best possible solution)

another way is

by using digital circuit to control the rail of capacitors.

i think these are fine

please let me know is there any possibilty beyond my solution.

 

[xuebi]

Thanks! Sreechoudhary.

Can you explain the three methods above a little more detailed?