28-nm “digital” CMOS generates 79 GHz radar signals – will enable radar-on-a-chip

February 18, 2014 // By Graham Prophet
Imec, in collaboration with Vrije Universiteit Brussel, Brussels, has succeeded in producing 79 GHz radar transmitter signals using only “plain digital” 28 nm CMOS. With an output power above 10 dBm, the transmitter front-end paves the way towards full radar-on-chip solutions for automotive and smart environment applications.

Millimetre-wave radar systems potentially offer range resolution finer than 10cm and an angular resolution finer than 10 degrees, and will be used in next-generation driver assistance systems to improve safety in poor-visibility conditions (dust, fog, and darkness) where image-based driver assistance systems fail. Conventionally, the high bandwidth and carrier frequency needed to achieve such high resolution, wide field of view and high angular resolution, translate into large, expensive and power hungry mm-wave antenna arrays. A low power compact radar technology will be key to enable the application of mm-wave sensors in next generation automotive and smart environment applications.

Imec’s continuous wave (CW) radar transmitter operates in the 79 GHz band. Implemented in 28 nm CMOS, with a supply voltage of 0.9V, it only consumes 121 mW and is fully compliant with the spectral mask imposed by ETSI. Phase modulation guarantees high resilience against interference and enables code-domain multiple-input, multiple-output (MIMO) radar.

These results were presented at the recent ISSCC2014 (San Francisco): “A 79GHz phase-modulated 4GHz-BW CW Radar TX in 28nm CMOS”; Giannini, et al.

After developing matching receiver functionality (by end 2014), imec aims at building a complete multi-antenna lab prototype by the end of 2015. Then, integration of ADCs and digital logic will lead to a full SoC.

Imec; www.imec.be