This paper proposes a Polarized Rotating Surface (PRS) in which the
middle layer is composed of two orthogonal open resonant rings of
different sizes, which is also an innovation of this structure. This
structure can convert TE/TM waves into TM/TE waves orthogonal to them,
and the polarisation conversion efficiency remains above 99% within the
bandwidth. Therefore, the decoupling method of this structure is
different from the traditional decoupling by blocking electromagnetic
wave propagation, and different from the introduction of additional
paths for neutralization and decoupling. Instead, polarisation isolation
is achieved by converting electromagnetic waves into their orthogonal
waves. Not only that, through electromagnetic simulation, the proposed
polarisation rotating surface can reduce the electromagnetic coupling
between two ultra-wideband horn antennas whose centers are 1 m apart in
the range of 5GHz ~19GHz by an average of 20dB and a
maximum of 30dB. The final experimental results demonstrate that, within
the operating frequency band, this PRS can reduce the coupling between
ultra- wideband array antennas by an average of 20dB.