  Power generation and synchronisation in Josephson junction arrays have
attracted attention for a long time. This stems from fundamental interest in
nonlinear coupled systems as well as from potential in practical applications.
In this paper we study the case of an array of junctions coupled to a
distributed transmission line either driven by an external microwave or in a
self-oscillating mode. We simplify the theoretical treatment in terms of
harmonic analysis and power balance. We apply the model to explain the large
operation margins of SNS- and SINIS-junction arrays. We show the validity of
the approach by comparing with experiments and simulations with
self-oscillating es-SIS junction arrays.
