Behavioral Modeling Including Low-Frequency Dispersion Effects and Application to PA Design

The increased risk of impairments resulting from ever increasing architecture complexity of novel communication systems requires much higher model fidelity of the RF chain in order to achieve cost effective prototyping, design and performance optimization of the overall system. Especially for the power amplifier, the model must accurately reproduce the nonlinearity and memory effects on the very wide variation domain (large frequency and power distribution over time) of the transmitted signal, in all the states of the system operation. Achievement of such a goal is a challenging problem that requires innovative modeling methodologies and measurement techniques. The talk will show how the problem may be efficiently apprehended from a mix of large-signal, small-signal three-tone measurements techniques using common VSG, VSA and VNA equipment. The methodology has been automated in a commercially available framework, that guides circuit and system designers through device characterization and model generation of a single component or a full RF chain, delivering a model compatible with common system level simulation tools. An illustration of the modeling of a wideband 3GHz down-converter chain will be shown.