This paper presents a novel polarisation dependent
EBG (PDEBG) surface which makes use of sheet vias. The
performance of the surface is analysed whilst varying the length,
thickness and inclination of the vias. It is observed that the phase
difference between the x-polarised and y-polarised component of
the reflected wave can be controlled by varying these
parameters. Furthermore, the surface exhibits a polarisation
conversion property with potential use in a variety of antennas