Lowest power, sub-GHz, multi-standard low-power wide-area transceiver IC

May 25, 2016 // By Graham Prophet
imec and the associated Holst Centre have designed a low-power radio chip for long-range connectivity in sensor networks and future cellular IoT applications; the design features high link budget and claims the lowest power of any such chip, for equivalent RF performance. It will be available to the companies that partnered imec in its development, and as licensable IP.

A number of stand-alone radio networks have emerged for long distance (km) transmission of IoT-class data (remote sensors, and the like), as well as narrow-band services associated with LTE cellular services. imec's radio chip can operate with a lower level of power than any other radio chip technology released to date for this role. The sub-GHz radio chip’s technology can serve multiple protocols including IEEE 802.15.4g/k, W-MBUS, KNX-RF, as well as the LoRa and SIGFOX networks, and future cellular IoT.


The radio chip operates in industrial, scientific, medical (ISM) and short-range devices (SRD) bands, covering 780 MHz to 930 MHz. The design offers a high level of interference rejection and lowest bill of materials by minimizing external components as compared to of-the-shelf available chips. The radio is implemented as a complete SoC including the RF front end, power management, an ARM processor,160 kBytes of SRAM and peripherals such as SPI, I ²C and UART. It features a targeted sensitivity of -120 dBm at 0.1% BER (1 kbps) and power consumption of 8 mW (Rx) and 113 mW (Tx) for 13.5 dBm output power. The receiver supports a wide gain range to handle input signals from -120 dBm to -15 dBm, corresponding to a large dynamic range of 105 dB. The PA features automatic ramp-up and ramp-down for ARIB spectral mask compliancy. Output power is controllable from <-40dBm up to 15dBm.


“With the foreseen release of the NB-IoT protocol in June 2016 by the 3GPP, it is clear that protocols such as NB-IoT, SigFox and LoRA are here to stay for the coming years,” stated Kathleen Philips, program director perceptive systems at imec/Holst Centre. “Our novel sub-GHz radio chip can serve multiple of these protocols and is an ideal solution for long-range wireless connectivity for IoT applications.”


Imec’s Industrial Affiliation program on the Intuitive Internet-of-Things (IoT) focuses on developing the building blocks for the future. The program