Ultra Low Power Wake-Up Radio Using Envelope Detector and Transmission Line Voltage Transformer

Abstract

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].

An ultra low power high sensitivity wake-up radio receiver with addressing capability

“…It is usual to realize this type of circuits using a Shottky envelope detector, MOSFET or ad-hoc ICs for the radio front end and, finally, a comparator to generate an interrupt. The works presented in [23], [24], [25] and [26] show similar architectures for ultra-low power WURs for WSN devices. They all drastically reduce the total network energy consumption by reducing the sensor node listening activities.…”

On the human body communications: wake-up receiver design and channel characterization

“…The WUR solutions are based on variety of different receiver architectures [7]: matched filter [11], radio frequency envelope detection (RFED) [12][13][14][15][16][17][18][19][20][21], uncertain intermediate frequency (U-IF) [22,23], sub-sampling [24,25], superregenerative oscillator (SRO) [8,9,26], and injection locking [27−29]. The design involves many tradeoffs; therefore, it is not straightforward to define, which architecture is best suited for a WUR.…”

Interactive UHF/UWB RFID tag for mass customization

“…4. As a comparison, the driving current of the state-of-theart passive UHF-RFID tags is several tens to hundreds micro-amperes (Reinisch et al 2011;Nilsson and Svensson 2013;Papotto et al 2014;Phan et al 2013). As a result, a semi-passive tag with a battery is more applicable for MC applications.…”