Power Calculations for Overmoded High Power Millimeter-Wave Devices

The microwave electronic efficiency of high-power microwave devices is derived from the ratio of total radiated power to input electron beam power. In this work, we are exploring different approaches to calculate the radiated power from high-power microwave and millimeter-wave devices. The total radiated power is usually obtained by integrating the measured radiation pattern in the far-field. For high-power microwave experiments, it is only possible to collect a limited number of data to estimate the total power. In addition, it is a challenge to map the radiation pattern in both the horizontal and vertical planes. One possible way is by fitting the data points using a curve fitting tool to find a mathematical expression and then integrating the function over the solid angle regardless of the operating mode. The power pattern data points can be interpreted as the radiation power density or the radiation power intensity. That is valid for the far-field region, which is not always possible for millimeter-wave range.