Comparison of Recently Developed Single-Bit All-Digital Frequency Synthesizers in Terms of Hardware Complexity and Performance

Internet of Things growth requires the development of low power and low cost wireless transceivers. Here, we present three recently developed all-digital frequency synthesizer architectures which can be used as transmitters for Internet of Things applications. These all-digital transmitters are based on different sigma-delta modulator architectures, varying in performance and hardware complexity. The operation principles of the three proposed architectures are described. Then, proof-of-concept FPGA implementations of these architectures are presented and compared in terms of hardware resources and speed. Their performance is tested using 32-QAM modulated signals. Finally, conclusions are drawn to help the reader select the most suitable architecture for a given application.