wideband impedance matching

Thread Starter


Joined Oct 7, 2009
Hey, I'm working on an impedance matching circuit that needs to match a 1.95+j2.0Ω source with a 50Ω load over a 370 Mhz bandwidth. I've come up with the design attached and it produces the output shown. As can be seen in the output the response is great until it reaches about 330 MHz and then it drops off fast for the last 70 MHz. I set my Q point at 0.707 because that's the Q point for a butterworth impedance matching circuit, but apparently I need a larger bandwidth. I know that some RF devices use RF transformers to achieve a larger bandwidth in an impedance matching circuit. Am I going to need to begin to look into those to get more bandwidth or is there some other approach I could take?


panic mode

Joined Oct 10, 2011
why not change capacitor values?
did you calculate or just simulate transfer function? it looks quite bumpy. it should be flat in pass band.