On the use of the Coulomb gauge in solving source-excited boundary value problems of electromagnetics

The advantages and difficulties associated with the use of the Coulomb gauge in solving source-excited boundary value problems of electromagnetics are examined. The correct dyadic Green's function for the Coulomb vector potential in a rectangular waveguide is derived to elucidate the discussion. The attractive feature of the Coulomb gauge is the explicit separation of the electric field into its lamellar and solenoidal constituents. A flaw in the usage of the Coulomb gauge in W.R. Smythe's text Static and Dynamic Electricity (1968) is noted and corrected.>