The main problem encountered by designers of reference measuring devices for moderate microwave power levels is how to overcome the contradiction between small dimensions of the waveguide channel and the need to dissipate comparatively high power in the absorbing sensitive element. Decreasing waveguide cross sections also increase technological difficulties associated with the manufacture of conventional microwave power converters. The above contradictions can be avoided if conventional devices with concentrated action (such as thermistors, wire bolometers, directional couplers)are replaced with bulk-action devices that allow higher power dissipation and expand the frequency range. However, such changes cannot be accomplished without using new materials for microwave power converters~ and without developing a new design theory and technique.