How to measure Bandwidth and Q of high-pass T-match circuit?

Hello all,

Here I attached the circuit and dB plots of its S11, S21 and ZM1. I designed this circuit for fr (center freq/resonating freq) =2.4GHz and Q = 5. From theoretical concept, I am calculating Bandwidth as
B.W = (fr/Q) = 480MHz.
How can I measure simulated Bandwidth and Q from the plot which I attached

for the given T-match circuit?






Regards,
Vinay Rao.

I dont know why are you measuring the BW from Q. Usually we measure BW from S21 and then calculate the Q of the circuit. Your filter seems to be high pass filter and high pass filter usually have cut off frequency rather than of BW.

Hello capcas,
Thanks for your reply. Yes it is high pass filter. What i defined "B.W = (fr/Q)" is one of the definition of Q. I designed this circuit for Q=5. How can i measure resulted Q from the simulation plot? For high pass, i have to measure cut-off frequency and then i got to find out 'Q' you mean?

Usually for high pass and low pass filter you measure Q by the rejection it provides, please look at Microwave Engineering by Pozar. In this circuit you are getting almost infinite Q because of ideal nature of selected elements.