An ultra-low power wake-up radio receiver using no oscillators is described. The radio utilizes an envelope detector followed by a baseband amplifier and is fabricated in a 130-nm complementary metal-oxide-semiconductor process. The receiver is preceded by a passive radio-frequency voltage transformer, also providing 50 antenna matching, fabricated as transmission lines on the FR4 chip carrier. A sensitivity of dBm with 200 kb/s on-off keying modulation is measured at a current consumption of 2.3 A from a 1 V supply. No trimming is used. The receiver accepts a dBm continuous wave blocking signal, or modulated blockers 6 dB below the sensitivity limit, with no loss of sensitivity.
IndexTerms-Blocking signal, complementary metal-oxide-semiconductor (CMOS), envelope detector sensitivity, radio-frequency identification (RFID), ultra low power, wake-up radio, wireless sensor networks.
I. INTRODUCTIONT HE RESEARCH on low-power radio technology is motivated by the needs from several application areas. Among these application areas are distributed wireless sensor networks, which may include chemical security monitoring [1], buried sensors for buildings and structure health [2], biotelemetry [3],[4], or surveillance in logistic chains [5]. These types of networks are sometimes referred to as Internet of Things (IoT), ubiquitous computing, or simply as radio-frequency identification (RFID). A common requirement is the need for ultra low power receiver solutions. The network node lifetime is determined by its power consumption and its battery capacity. Energy scavenging from mechanical vibrations, thermal gradients, or electromagnetic fields could increase the lifetime or eliminate the need for batteries. Exclusion of batteries may drastically change the service required to maintain the network, but with available radio technology this will also severely reduce the communication range for the nodes. A common accepted dc power consumption level where energy scavenging is feasible for a node is around 100 W [6].