  In this letter, we investigate joint application of reconfigurable
intelligent surface (RIS) and vertical beamforming in cognitive radio networks
(CRN). After properly modeling the network, an optimization problem is formed
to jointly design the beamforming vector and tilt angle at the secondary base
station (BS) as well as the phase shifts at the RIS with the objective of
maximizing spectral efficiency of the secondary network. The optimization
problem is non-convex; thus, we propose an efficient solution method for it.
Numerical results show that adding a RIS and optimizing the radiation
orientation, can significantly improve performance of the CRNs.
