<正>The design and measurement of a broadband passive tripler is reported.More simple structure and fine performance is attained by using the configuration of directly coupling between lower waveguide and beamlead diodes.Measurement results show the conversion loss is 18.2±2dB,the return loss is more than 6dB and the phase noise deterioration is less than 10.5dB from 33GHz to 50GHz,which are the output frequency of the passive tripler.