This work examines and implements two different techniques for the estimation of the capacitance and impedance of microstrip-like open structures. Both theories, one developed by Yamashita and Mittra and the other by Itoh and Hebert are based on variational methods. The results for the capacitance and impedance of a microstrip-like structure are calculated numerically and compared with measurements taken using a sample. The results presented in this thesis indicate that the first method produces results with large error and it can be used for microstrip structures with only one strip. The second method produces very accurate results for the microstrip structure under consideration and is the one recommended. / Master of Science