The propagation of linear lower hybrid waves in an inhomogeneous plasma is studied under the assumption that the wave field has a relatively narrow spectrum of wave-numbers. The lowest-order electromagnetic correction, neglected in the electrostatic approximation, is included. It is shown that this electromagnetic correction can produce focusing of the wave envelope in the outer layers of typical large-tokamak plasmas. This focusing is a linear effect due to the opposition of thermal and electromagnetic dispersion.