  We investigate photoproduction of $\phi$-mesons off protons within a
coupled-channel effective-Lagrangian method which is based on the K-matrix
approach. Since the threshold energy of the $K\Lambda(1520)$ channel is close
to that of $\phi N$, the contribution of this channel to $\phi$-photoproduction
near the threshold energy region may give rise to some unexpected structures.
In the transition amplitude $K\Lambda(1520) \to \phi N$, the kinematics allows
an intermediate kaon to be on-shell. This happens in the energy region where a
peak structure has been observed in $\phi$-photoproduction. In our calculations
the on-shell kaon effect indeed reproduces a peak structure, however, with a
magnitude that is far too small to explain the observed effect. As a following
step we introduce a nucleon resonance in our model. The coupling of the
resonance to the $K\Lambda(1520)$ and $\phi N$ channels is not suppressed by
the OZI rule if the resonance contains a dominant hidden strangeness component.
We find that the resonance can reproduce a peak structure of the correct
magnitude at the right energy. We also investigate the effects of coupled
channels and the resonance on the angular distribution and the spin density
matrices for $\phi$ photoproduction.
