Higher-order vector finite element-boundary integral method for cavity-backed microstrip antenna on a dispersive substrate

The vector finite element-boundary integral method (FE-BI) is adopted to calculate the input impedance of a cavity-backed microstrip antenna on a dispersive substrate, where higher order hexahedral basis functions are employed to expand the unknown field of the FEM functional formulation. Numerical results presented illustrate that the higher order approach performs more efficiently than the lowest order one.