Non-linear device characterization and modeling for technology development and PA design
Evolving performance requirements for Cellular PA’s and WiFi products drive for tailored to application and effective GaAs technology evaluation and development. Thus, technology benchmarking for new products requires fast data turn around, efficient epi optimization and down-selection based on non-linear (NVNA based) device characterization, in-depth understanding of device characteristics, reliable test vehicles and accurate correlation of device level data to power amplifier (PA) design. Efficient and predictive on-wafer device characterization methodology and data analysis flow was developed to provide accurate input to process, technology development and design teams toward faster adaptation of new technologies.
Non-linear device characterization is based on use of behavioral model to calculate and analyze power performance of the test vehicle in a virtual Average Power Tracking (APT) and Envelope Tracking (ET) mode. Application of various waveform data specific to PA design that technology is targeting provides in-depth insight for trade-offs in power performance based on CW data that are easy to interpret and understand by design teams.
As part of technology development and benchmarking flow, test vehicle designed as a breakout of PA output stage is used in on-wafer device characterization, straightforward to simulate and model for new epi/process variants. Thus, modeling is used as a tool to predict performance advantage before these variants are fabricated and model for new material can be tested in simulation for full PA when such simulation bench is available.
Efficient use of test vehicle with non-linear (NVNA based) data collected over large set of load and bias conditions was proven to be very useful and practical tool for epi, device development, model validation and design evaluation under conditions that are correlated to given PA specs.