Recent Advances in Linearization Techniques for Frequency Multiplier-Based Transmitters Driven With Vector-Modulated Signals

The shift toward millimeter-wave and sub-terahertz frequencies in communication systems presents significant challenges in transmitter design, particularly in generating wideband, high-data-rate signals with adequate power and linearity. Frequency multiplier (FX)-based architectures have emerged as promising solutions for signal generation at these frequencies, but the inherent nonlinearity of FXs poses challenges to maintaining signal integrity. This article reviews recent advancements in digital predistortion (DPD) techniques aimed at mitigating the nonlinear distortions in FX-based transmitters, particularly when driven by vector-modulated signals. By providing a comparative analysis of state-of-the-art DPD approaches and highlighting key innovations, this work offers critical insights into the strengths and limitations of current methods and outlines future research directions for enhancing the linearization of FX-based transmitters in next-generation communication systems.