Direct Real-Time Power Measurement of a High-Power Electron Cyclotron Maser by a Simple One-Point Schottky Detector Signal

Measurements of the absolute power of high-power millimeter/THz wave generators have been considered to be highly variable and to occasionally produce faulty results owing to experimental difficulty. In this study, we propose a calibration-free method for real-time power measurement of an electron cyclotron maser system, a so-called gyrotron. We demonstrate the feasibility of the method by using a recently developed W-band gyrotron with a peak power of tens of kilowatts. The technique is based on transmitter antenna power measurement by using the Friis transmission equation with a defined gyrotron antenna gain. The new technique will allow extremely simple and accurate real-time measurement of output power over a wide dynamic range ( dB) for continuous wave sources to high-power millimeter/THz wave sources with nanosecond pulse lengths.