Hi
I am setting up a receiver design. I have two mixers in this with conversion gain of -6dB. However, after I do a system analyses, the gain of the mixer drops from -6dB to almost -7dB. I am unable to understand why this happens. I am attaching my program
Thank you
Rashmi
[file]receiver example 2.wsx[/file]
I am setting up a receiver design. I have two mixers in this with conversion gain of -6dB. However, after I do a system analyses, the gain of the mixer drops from -6dB to almost -7dB. I am unable to understand why this happens. I am attaching my program
Thank you
Rashmi
[file]receiver example 2.wsx[/file]
Thanks
Rashmi
I'm cheating by using the new version (2006.10 - shipping in a week) but we've added a new measurement (DCR - channel resistance) and it shows a mismatch at the outputs of the two mixers, hence the gain reduction (I think).
You don't really want to "fix" this. SPECTRASYS is incredibly good at telling you exactly what is going to happen in a real-world problem. What happens in the real-world is rarely what a spreadsheet would indicate.
If I remove the mismatch by setting the filter to no ripple and I set P1dB high for the first mixer, I get 6dB of conversion loss.
You could also insert a 0-gain buffer after the mixer to isolate and impedance match, and set P1dB high on the mixer to see the same 6dB conversion loss.
Or you could switch to a butterworth filter, which won't have any ripple in the passband, bump up P1dB, and again you get 6dB of loss.
Mark