Linear Efficient Broadband Transmitter Architecture at mm-wave frequencies

There is an ever-increasing demand on low-cost high-throughput wireless front-ends. Such high-throughput front-ends support broadband data transmission (multi-Gbit/s) for a wide variety of sensors and unmanned platforms in situational awareness, monitoring, and reconnaissance. Their wideband nature also supports the deployment of broadband communication/radar combo-systems, as well as numerous emerging commercial applications such as 5G networks, augmented reality/virtual reality systems. The transmitter often governs the total output power, energy consumption, linearity, and bandwidth of the communication/radar front-end, which respectively determines the communication distance, energy efficiency, signal-fidelity/emission, and modulation rates. Although mm-Wave transmitters supports large signal bandwidth in theory, existing hardware exhibits limited output power and compromised efficiency, in particular at deep power-back-off situation. Moreover, the linearity of such high-throughput transmitters cannot be enhanced using conventional techniques, such as feedback-based digital pre-distortion (DPD), which are unable to support multi-Gbit/s bandwidth since it requires impractical baseband computation complexity. In phase I, Digital Analog Integration, Inc. and Georgia Tech team have demonstrated the feasibility of the proposed watt-level broadband dual-mode mixed-signal mm-wave Doherty transmitter. In phase II, we will work closely to investigate an all-silicon and silicon/compound-semiconductor heterogeneous integration platforms for the implementation of our novel Doherty PA based highly efficient transmitter architecture.