From Sensitivity to Selectivity: Circuit Design Challenges in WuRX

Wake-up receivers (WuRX) deliver always-on connectivity at microwatt power levels. Designers face the fundamental challenge of achieving both high sensitivity and strong selectivity under extreme energy constraints. This talk shows how power allocation across RF, frequency generation, baseband, and digital domains drives overall performance. I will compare architectures in terms of sensitivity, power, and selectivity trade-offs, and highlight circuit-level issues such as noise, blocker resilience, leakage, and duty-cycling. I will also present emerging techniques that improve selectivity while preserving energy efficiency.