In this paper we present a shared-aperture
polarisation reconfigurable microstrip array designed to resonate
at 11.5 GHz with a gain bandwidth of 2 GHz (~17%). The
polarisation reconfigurability (both linear and circular) is
achieved using two orthogonal and independently-fed sub-arrays
that are intertwined together on the same aperture. Each subarray
is fed through one port and a feed network that distributes the
power among the array elements incorporating Taylor taper
distribution to minimize the sidelobe level. The array has low
cross-polarisation level (<-20 dB) and good port isolation (<-24
dB). The shared aperture and absence of active switching devices
provide better control of polarisation selection with almost no
insertion loss. A near-field metasurface based steering system is
also presented and applied to the array for one- and two-dimensional beam steering. The results are verified through model
simulations and measurement of the fabricated prototypes.