Unraveling the Missing Link in Low-power Communication: An Autodyning Receiver Architecture that Achieves a Long Range

Wireless communication remains the most power-intensive operation in embedded systems. Decades of research have enabled radio transmitters to operate at power levels as low as tens of μWs while maintaining practical communication ranges. However, achieving power-efficient reception over similarly useful distances has received significantly less attention. State-of-the-art low-power receivers typically rely on Schottky diode-based envelope detectors, which are inherently limited in sensitivity and unable to support complex modulation schemes. We introduce SoMix, the Single Oscillator Mixer receiver, a novel architecture that uses tunnel diode oscillators to overcome these limitations. Specifically, we demonstrate the autodyning property of tunnel diode oscillators, allowing a single circuit to generate both a carrier signal and perform signal downconversion, thus merging two traditionally power-hungry analog tasks into one energy-efficient step. The SoMix front-end consumes less than 100 μW while supporting high-sensitivity reception. Through injection-locking, SoMix stabilizes its tunnel diode oscillator using even a weak external carrier signal, allowing it to receive frequency-modulated transmissions from distances greater than 100 meters in line-of-sight environments. We also demonstrate that the SoMix exhibits robustness in complex real-world scenarios. SoMix outperforms state-of-the-art receivers in power, range, and functionality.