As the pulse power and high power microwave source technologies gradually matured, technologies for enhancing the output capacities of high power microwaves are becoming more and more attractive. In this paper, two different methods for the increasing of X band microwave powers are discussed: diplexers based on microwave filter and photonic crystal. For the case of diplexer based on microwave filter, the dual channel X band microwaves transmit through the filters with high efficiencies, the polarization and radiation directions for the microwaves are the same. With the application of metal photonic crystal, the reflection and transmission of TE/TM polarized X band microwaves are realized simultaneously; thus, the dual channel microwaves have the same radiation direction. A pulse of 25 ns, 3.9 GW has been successfully obtained. However, according to the experimental results, the internal breakdown in these devices limits their power handling capacities when the peak power and pulse duration of the microwaves increase. In the end, several methods for enhancing the power handling capacities the diplexer have been proposed.