Scalable MIMO radar utilizing delta-sigma modulation-based frequency-division multiplexing technique

This paper describes the realization of a scalable MIMO radar system utilizing several transceiver (TRX) chips and patch array antennas. It uses a suitable antenna configuration that enables a maximum number of virtual array elements to improve the angular resolution of the radar system. The TRXs, which are implemented in a Silicon-Germanium technology and include an LO buffer as well as a frequency multiplier, require only a single low frequency LO signal from an external frequency synthesizer. The proposed scalable sensor architecture simplifies the routing of the LO signal and enables the cascading of multiple TRXs to build a MIMO radar system using time and frequency division multiplexing based on delta-sigma modulation. Radar measurement using the digital-beamforming method with 5-GHz modulation bandwidth and 4 virtual array elements was performed to show the applicabilty of the proposed system.