Load curve estimation for microwave ovens: Experiments and electromagnetic modelling

Load curves of two representative household microwave ovens are constructed experimentally and by electromagnetic simulations. The load curve shows power dissipated in a water load as a function of the load size, and is considered a measure of oven performance. The paper points to several assumptions inherent in the standard experimental procedure and provides their field-theoretical sense. Further, measured and simulated load curves are shown in good agreement for loads above 0.2 l. For small loads, the measured values fall within a wider band between the numerically predicted maximum and minimum dissipated power values, which result from uncertainty of the magnetron operating frequencies combined with the resonant character of the reflection coefficient curves.