It was found that there are dual higher order modes which have the same circulation direction at W band based on the calculation of boundary value of electromagnetic field. The dual modes are close to each other. They can be used to realize dual frequency circulator,or to get broadband performance by partially staggering them. Experiments given in this paper verified the theoretical prediction. A broadband waveguide junction circulator at W band was developed. The performance of 8 GHz bandwidth with 18 dB isolation was obtained by staggering the dual higher order modes.