The characterization of small complex CP ramic packages with (monolithically) integrated microwave circuits is investigated using full-wave methods In order to correctly design packaged radio frequency (RF) chips, the consideration of the package has become an indispendible part of the chip design process, as the electrical properties of the package have a great impact on the performance of the KF chips For an effectise simulation, a segmentation hetween the chip and i& immediate environment, such as, the package, is investigated, and a suitable interface hetween chip and package is proposed to prove the validity of the interface, the simulation of the packaged RF device, which is pieced together from the full-nave simulation of the package and the simulation of the RF chip, i s compared to the corresponding measurement Simulation and measurement of the packaged RF device w e e very well.