Sorry to bother you again. I did what you said. I put a 100ohm resister in parallel for the input, and it works fine. Then I added a rf attenuator at the output port to match the impedance. But it seems like there are still some portion of the signal got reflected by the attenuator, so the power output is 10-20dB's lower than what it should be. I just want to ask what should I do to eliminate the reflection? Should I use a balun instead, or can I replace the 453ohm resistor at the output port with a 50ohm one? Thank you so much for your help.
Admin note: this is a branched question from the following thread: