This is my first post on the forum! I am a student so thank you and bear with me.
I am working on an 8-path mixer design, and trying to measure the Noise Factor. I am using a LO of 2.485GHz.
Currently, the bandwidth of the mixer is right, it appears that S11 is about -26 dB, I believe the design seems OK.
I am having trouble getting results that seem right for NF using pnoise analysis in Cadence.
I'm not sure the correct way to do this - it seems that for a downconversion mixer you usually use -1 as refSideBand, but that doesn't make a lot of sense here, since the LO and RF frequencies are equal.
When I set the refSideBand to -1, with the beat frequency set as 2.485GHz and measure NF at baseband, the NF is really high, like 10-20 dB which seems way too high!
I've attached some photos of the schematic, my simulation results, the schematic (it only shows a few of the 8 paths) and the pnoise analysis setup.
Any tips would be appreciated.