During this project we studied cavities as an alternative method to stripline resonators, to create an oscillating magnetic field. We were able to simulate different cavity designs and reproduce theoretical results as a numerical simulation and experimentally. Thus getting familiar with cavities and studying how their design influences the TE011 mode in which we lay our interest. It was shown that with cavities one could reach a higher quality factor than with stripline resonators. We also found out that in order to make a cavity small enough to be useful it is indispensable to use dielectric materials and studied the behavior of a few possible cavity designs.