Development of a Low Reflection Dummy Load for Calorimetric Power Measurements in High-Power Millimeter Wave Systems

We developed a prototype low reflection dummy load for calorimetric power measurements in high-power millimeter wave systems. The dummy load is featured by low reflection of millimeter waves by an internal cylinder designed for increasing the length of the ray trajectory in the dummy load. This structure prevents the millimeter wave reflection from the dummy load by absorbing the waves by the inner surface of the cylinder. Initial tests at high powers of up to 0.5 MW for 0.25 s were successfully able to measure output power with lower reflection back to the source than that of conventional short pulse dummy loads used in the past. (C) 2022 The Japan Society of Plasma Science and Nuclear Fusion Research