  In the literature, few constructions of $n$-variable rotation symmetric bent
functions have been presented, which either have restriction on $n$ or have
algebraic degree no more than $4$. In this paper, for any even integer
$n=2m\ge2$, a first systemic construction of $n$-variable rotation symmetric
bent functions, with any possible algebraic degrees ranging from $2$ to $m$, is
proposed.
