The present disclosure relates to a reader, such as a reader for a physical access control system. The reader can include first and second antennas, each designed or configured for receiving ultra-wide band (UWB) signals. The reader can also include a mounting plane configured for mounting the reader to a surface. An axis aligning the first and second antennas can be arranged substantially perpendicular relative the mounting plane. A material can be provided between the first and second antennas The material can have a thickness that defines a distance between the first and second antennas of less than a half wavelength of the UWB signal through air (λA/2), the material configured to slow down electromagnetic waves passing therethrough such that the thickness of the material provides an effective separation distance of the first and second antennas of at least a half wavelength of the UWB signal through air (λA/2).