Comparative Studies on the Performance of Low Power Transmitters for Wireless Sensor Nodes

Problem statement: Power consumption was one of the most challenging aspects to design low power wireless sensor nodes. The objectives of the study were to (i) Design low voltage, low power transmitters for wireless sensor nodes and (ii) Compare and analyze the performance of the transmitters. Approach: The transmitters employed direct digital modulation scheme to reduce the power consumption of the sensor nodes. Emphasis was placed on observing device reliability constraints at low power to maximize the life time of the wireless sensor nodes. Results: The Amplitude Shift Keying (ASK) transmitter consumed a power of 400.104 μw from the 1.2 V supply. The Frequency Shift Keying (FSK) and Phase Shift Keying (PSK) transmitters consumed 520 μw and 5.2 mw respectively at 2.4 GHz. The transmitters suitable for low voltage, low power wireless sensor nodes were designed and implemented in 120 nm CMOS technology Conclusion: The performances of the ASK, FSK and PSK transmitters were analyzed and were compared with the previously reported low power approaches operated in similar frequency ranges.