Hello everyone! Thank you for looking at this thread. I am trying to design a 10th order Butterworth filter using passive elements (i am using the Insertion Loss Method, and using prototype numbers). So far, I have designed a 5th order Butterworth filter, and I am planning to cascade two of them together. My questions about this are: 1. Do I need a matched attenuator in between them? If so, 2. Should I design the matched attentuator to have a Zin = Zout = 50 Ohms (since the source and load resistance of my filters are 50 Ohms) 3. And if looking into the matched attenuator gives an impedance of 50 Ohms, can I remove the 50 Ohm load resistor from my first filter? If this is confusing, and you are willing to help [ please! :) ], please let me know and I can email you a MS Word document of my work so far. Thanks to all for your time!