Pi-Matching Network Simulation in LTSPICE

[ssgill2]

Hello All,

I am currently working on a simple project which involves designing a pi-matching circuit for a source resistance of 50 ohms and load resistance of 800 ohms. The frequency of operation (center frequency) given to me is 800 MHz and bandwidth specification given to me is 25 MHz. From this information, I calculated my required Q factor and designed my pi-matching networks. I have used the block DC format.

Using the .net and .ac commands, I simulated my S11 parameter to ensure it is less than -10 dB as that means good matching. The question is how do I interpret the S11 simulation? It just lines going up and down to me. In the attached file, I included the S11 plot and my schematic. My S11 is in the mdB range so I assume I have designed a good matching circuit?

Thanks for reading
Simardeep Gill

 

[AnalogEL]

Hello!

It's already been ten days, have you already solved your problem?

I checked and your pi network does indeed match 800Ω to 50Ω well, but it looks like you have your both your source and load set to 50Ω in your simulation. Fixing that would be a first step,,,

 

[ssgill2]

Hi thanks for replying. I got it working now. There were 2 issues, one was my load needed to be 800 ohms and my .AC frequency range should needed be much bigger.

Thanks