Radiofrequency energy that is captured by a radiofrequency power harvester is stored in a storage capacitance. One or more user circuits are supplied with energy stored in the storage capacitance. The harvester operates in alternated charge and burst phases with captured radiofrequency energy stored in the storage capacitance in the charge phases and supplied to the user circuits in the burst phases to perform user circuit tasks. In response to detection of completion of the user circuit tasks in a burst phase, the harvester causes operation to shift to the next charge phase.