Package-Level Reconfiguration of RF Matching Networks Using SMD Components

Digital power amplifiers provide an unprecedented level of flexibility in their ability to operate on different signals using simple reprogramming of the digital signal processing, but their output matching networks must be redesigned for different frequency bands. This involves a redesign of part of the back-end-of-line mask set at a great cost. We present a package-level reconfiguration technique that allows a single transmitter to be reconfigured for multiple frequency bands, or different output power levels by soldering different surface mount device (SMD) components directly to the surface of the die, saving design and fabrication cost while delivering similar performance. We demonstrate the technique on a multiphase transmitter IC, showing optimized operation at three different frequencies using soldered SMD components to reconfigure the matching network of the IC at the package level. The transmitter's linearity and performance are validated using a 5-MHz, 64-QAM LTE signal.