The Designer's Guide Community Forum

The Designer's Guide Community Forum
https://designers-guide.org/forum/YaBB.pl
Design >> Analog Design >> why is the output of GM-C bandpass filter still resonating in voltage reference?
https://designers-guide.org/forum/YaBB.pl?num=1318646725

Message started by dashing on Oct 14^th, 2011, 7:45pm

Title: why is the output of GM-C bandpass filter still resonating in voltage reference?
Post by dashing on Oct 14^th, 2011, 7:45pm

Hi all, I encountered a problem of the gmc bandpass filter, which is like the picture attached saying, the output of the filter is not actually the envelop with 1M LO and 10k signal, furthermorem the tran output of the cadence seems to be resonating in reference voltage, in contrast, I think it should be zero resonate in dc voltage reference.
So I got confused abt it and I don not know what is wrong with it? could anybody help me and give me any guidance? that will be appreciated. thanks a lot~~
plus: (the LO is square wave with 1MHZ and the signal is around 10K, thus the last two graph showned in the picture is the output of the gmc filter)