Effects of Diffraction, Dispersion, and Absorption of Electromagnetic Waves in the Diagnostics of High-Power Microwave Pulses Using Wide-Aperture Liquid Calorimeters

Using a simple theory and finite-difference time domain (FDTD) simulations involving the Lorentz model, we demonstrate some problems in the determination of pulse waveform, amplitude, and peak power of high-power microwave pulses, when performed together with calorimetric measurement of the pulse energy, arising from the wave diffraction as well as from its dispersion in the absorbing liquid. Considering few typical pulse shapes and other experimental conditions, we outline the general limitations and recommendations for performing such measurements.