We analyze the use of edge finite element methods to approximate Maxwell's
equations in a bounded cavity. Using the theory of collectively compact ope
rators, we prove h-convergence for the source and eigenvalue problems. This
is the first proof of convergence of the eigenvalue problem for general ed
ge elements, and it extends and unifies the theory for both problems. The c
onvergence results are based on the discrete compactness property of edge e
lement due to Kikuchi. We extend the original work of Kikuchi by proving th
at edge elements of all orders possess this property.