We present a numerical method for the analysis of translationally invariant systems with anisotropic and dispersive electric and magnetic properties. This material model enables us to calculate the mode structure of photonic devices such as photonic crystal fibres (PCF) containing inclusions with anisotropic, conducting, magnetic, or negative index materials. The method is based on the popular plane wave (PWM) discretisation scheme applied to the generalised vectorial transmission line equations. The analysis is focused on the calculation of radiation losses. For this purpose we consider a uniaxial perfectly matched layer (UPML) termination of the otherwise periodic system. We asses the accuracy of the method and the properties of spurious modes created inside the UPML.