I'm designing a simple diode ring mixer for down-conversion from 1.5G to 200k. I want a band-pass LC pi-filter on the mixer IF output.
I've designed the filter for 50R source and load impedance by using a low-pass butterworth prototype and used the usual equations to scale and transform into a band-pass at my center frequency of 200k.
My LTSpice simulation shows the input impedance is only 50R at the center frequency, dropping to 0R in the stop band.
Should I be concerned that the filter wont absorb mixer spurs and harmonics in the stop band and will instead reflect them back into the mixer?
What is best practice for terminating an IF output with a narrow bandwidth?