Linear arrays of sources embedded inside a thin material slab are designed such that they radiate the same fields as a circular array of radiators in free space in a two-dimensional configuration. The design is based on the coordinate transformation approach, where a circular domain containing a distribution of line sources is transformed into a rectangular slab. The source distribution in the transformed space forms two closely-spaced linear arrays and the resulting material slab is matched along the boundary with free space. Full-wave simulations are performed for verification.