A Beam Steering Transmitter Prototype for IOT Communications

This paper discusses the design, implementation and evaluation of a phased array transmitter for Internet of Things communications based on the local oscillator (LO) phase shifting approach. The proposed architecture is made up of a four channel LO synthesizer, a radio frequency (RF) frontend module and a linear array of patch antennas. The LO synthesizer is based on a revised DDS-PLL architecture, is centered at 2.453-GHz and implements mutual phase shifts among its output channels in the [0° 360°] range with an 8-bit resolution. The RF frontend module performs the intermediate frequency (IF) signal up-conversion (at 3.350-GHz) and all signal conditioning operations required to drive the antennas. Actual measurements are reported at block-and system-level.