I drawed a 1-port equivalent circuit model which has lumped L and C parameters and a microstrip for an antenna structure using ADS. I measured the S11 using Network Analyzer. I know the desired length and width of the microstip and I like to optimize the L and C values to curve-fit the measured S11 using ADS.
Can someone point me to the right direction how to obtain the L, C values?
Find a copy of Antenna Theory by C.A. Balanis. He does an excellent job of going through the equivalent circuit analysis for a microstrip patch antenna. The equations are pretty big and intertwined. It'd be most expedient if you read the section and understood how the equations were developed, and how they interact (especially since some of the aperture-coupling equations are based on Bessel functions... but can be approximated with decent accuracy).