Embedded passive functions for RF and mixed-signal circuits

The drive to further miniaturize and reduce the cost of portable electronic devices has recently focused on the task of integration as the passive functions. Integration, especially for RF and mixed-signal circuit has unique requirements due to the frequency of operation which allows for lower component values yet limits the upper frequency of operation. A view into a modern mixed signal product such as a cellular phone, camcorder or PDA shows both the success of integrated circuit technology and its failure. Virtually all of the active functions of these devices are contained in a few, highly integrated specialized IC´s based on silicon technology with some specialized IC´s built from GaAs for the highest frequency requirements. Passive components, inductors, capacitors, and resistors, by contrast, show little or no integration with each schematic requirement realized by the soldered attachment of a single discrete device to an interconnect board. This paper presents an analysis of how feature sizes and tolerances affect the performance of RF passive functions. Proposed methods for improvement of the device characteristics are proposed