Thank you very much for your response.
I have an other question.
What do you mean by calibration setup ? Do I need to calibrate the board every time I set up ?
For Example, I have put 15 pf capacitor to measure its impedance characteristics. But its not showing the correct magnitude and phase delay by -90 degrees.
For any capacitor, the magnitude of impedance must decrease with increase in frequency. But When I connect a capacitor in Z and change capacitor value to 15 pf in Complex impedance section, I am not getting the correct characteristics that normal capacitor exhibit.
Do I need to change the value of Capacitor to 15 pf in the Calibration Impedance section of EVAL AD5933EBZ software ?
Please make clear why Rfb(Feedback resistor) is used ?