Calibration and self-test of RF transceivers

In the last few years cellular market well exceeded 1.3B cellular mobile devices shipped per year. The ongoing economic-driven shrink in technology towards nanoscale CMOS enables increased functionality in even smaller silicon area, however, technology effects including process variation, variability, temperature effects, flicker noise etc. put stringent challenges on the design and have significant impact on the production yield. Due to the huge volume yield, testing and Automated Test Equipment (ATE) have become a major cost factor in RF production. At the same time integration level and complexity of RF transceivers and SoCs have increased due to huge diversity of mobile communication standards ranging from 2G/3G to 4G, WLAN, BT, and GPS. RF devices are no longer purely RF devices. They integrate RF, analog and digital functions, all working together enabling the device to test and calibrate functions autonomously. This paper summarizes the key developments and trends in RF-BIST, with particular attention to improvements in testing and calibration of PLL loop-gain, second order modudulation, and I/Q impairments.