As I said in the other post, pxf analysis you specify the range of output frequencies you're interested in and where the output of the circuit is, and then you can plot the transfer function from a source (e.g. your RF input source) at different sidebands. So being able to find the transfer function from both the desired input frequency and the image frequency you can find out how well your circuit rejects the image. What isn't so straightforward is whether you are trying to combine the I and Q in some way - it's not entirely clear what you are trying to measure or what you exactly mean by "Image rejection plot". The simulator merely measures the transfer function (call it conversion gain if you like) from a sideband of the input source to the specified output frequency band. Regards, Andrew.
↧