The radio significantly reduces the power consumption of the overall sensor system compared to off-the-shelf radios. As a result, the autonomy of the device is increased, or more functionality can be added to the sensor device, increasing its quality, functionality and/or performance. Or, the battery size can be reduced, resulting in a smaller device, which in case of wearable systems, adds to the comfort of the user.
The 2.4 GHz radio is implemented in 90-nm CMOS technology. Using a highly energy efficient architecture and optimizing the most power hungry building blocks, resulted in a 2.4 GHz radio with world-class energy efficiency while supporting the most common standards for mobile sensor networks (BLE®, ZigBee ® and IEEE802.15.6).
The energy-efficient radio architecture has a suitable LO frequency plan and several efficiency-enhancement techniques for the critical RF circuits. As a result, the radio achieves a DC power of only 3.8 mW at 1.2 V supply for the receiver and 4.6 mW for the transmitter. This is 3 to 5 times more power-efficient than the current state-of-the-art Bluetooth Low Energy solutions. The measured RX noise figure is 6 dB, resulting in an excellent sensitivity in each standard (-100/-98/-96.5 dBm for Zigbee/BLE/MBAN). With a measured IIP3 of -19 dBm at the maximum front-end gain, the RX can accommodate the BLE intermodulation test level to -40dBm (the specification is >-50 dBm).
These results were presented at the 2013 IEEE International Solid-State Circuits Conference (ISSCC) in San Francisco.