The Designer's Guide Community Forum

The Designer's Guide Community Forum
https://designers-guide.org/forum/YaBB.pl
Simulators >> RF Simulators >> Rx+ baseband filter and VGA overall voltage gain simulation?
https://designers-guide.org/forum/YaBB.pl?num=1220108477

Message started by wccheng on Aug 30^th, 2008, 8:01am

Title: Rx+ baseband filter and VGA overall voltage gain simulation?
Post by wccheng on Aug 30^th, 2008, 8:01am

Dear all,

I have a Rx chain (included LNA+mix1+mix2) + baseband filter and VGA. I have combined all together and run the PSS + PXF in order to get the overall voltage gain. However, the simulation result is strange to me. It gives the M-shape voltgae gain and the voltage different is 10dB. However, the voltage gain flatness of Rx chain is within 1.5dB. The gain flatness of baseband filter+VGA is within 1dB. Why the voltage different for overall chain is 10dB and give the M-shape curve? Is there any special setting for this kind of the system? If yes, could you teach me the simulatino setting using SpectreRF?

Thanks

Title: Re: Rx+ baseband filter and VGA overall voltage gain simulation?
Post by pancho_hideboo on Sep 4^th, 2008, 10:57pm

wccheng wrote on Aug 30^th, 2008, 8:01am:

I have a Rx chain (included LNA+mix1+mix2) + baseband filter and VGA.

What is a value of local frequency for mix1 and mix2 ?

wccheng wrote on Aug 30^th, 2008, 8:01am:

I have combined all together and run the PSS + PXF in order to get the overall voltage gain.
It gives the M-shape voltgae gain and the voltage different is 10dB.

Just does it show gain including image response of mixer ?

wccheng wrote on Aug 30^th, 2008, 8:01am:

However, the voltage gain flatness of Rx chain is within 1.5dB.

Do you evaluate this using PSS/PXF with same simulation condition as total combination ?

Although you see gain including image response in total combination, you don't see image response in Rx chain ?