Need Advice on Gain Control Circuit

[suling]

A wideband CMOS LNA is designed based on resistive shunt feedback, noise canceling technique. A gain control of 24dB is required from this LNA. However, only 8dB of gain control is implemented in the current design (through changing resistance in the feedback path) in order to address a <-8dB input return loss prior to each gain step change. Need some advice to realise the remaining 16dB of gain control. Thanks.

 

[tony_lth]

You can use a VGA at the last stage for LNA.

 

[suling]

Hi, Tony, any recommendation on VGA design?

 

[tony_lth]

I don't know anything about MMIC design, I only use packaged MMIC.

 

[vfone]

https://www.ep.liu.se/ecp/008/posters/020/ecp00820p.pdf