A Modulator-less Beam Steering Transmitter based on a revised DDS-PLL Phase Shifter Architecture

Abstract

This paper details the design and implementation of a modulator-less beam steering transmitter based on a revised DDS-PLL phase shifter architecture. The proposed topology targets low data rate communications for Internet-of-Things systems, and has been demonstrated using an FPGA evaluation board and a custom PCB with four PLLs centered at 2.453-GHz. Measured system performance for an experimental 32-kbps data rate achieved through a 16-PSK modulation scheme are discussed. The proposed architecture is frequency independent, can be used in multi-band devices and has the potential for being integrated as an RF System-on-Chip.

Keywords

• direct digital synthesizer (DDS)
• phase-locked loop (PLL)
• modulator-less
• beam steering
• polar transmitter
• low data rate communications
• Internet-of-Things (IoT)