Abstract: Termination circuits for backscatter communication in an integrated wake-up receiver tag device. A reflective termination circuit includes a first branch having an open load and a shorted load with first branch offset reflection coefficients and with a connection to an antenna. A second branch has a capacitive load and an inductive load with second branch offset reflection coefficients and with a connection to an antenna. A MIMO termination circuit includes plurality of transmission lines each providing a unique delay that is offset compared to other ones of the plurality of transmission lines. Switched connections to a corresponding array of antennas introduce a delay between a received and backscattered signal at each antenna in the array of antennas.

Abstract: A method for waking a transceiver for communicating directly with commodity Wi-Fi transceivers (TRXs) via backscatter modulation in an integrated tag device includes sensing an incident Wi-Fi-compliant wake-up signal with a wake-up stage. Upon wake-up, a payload packet is sensed with a sync stage, the sync stage having higher bandwidth and power than the wake-up stage, the sync stage enabling a backscatter transmission circuit in sync with the payload. A backscatter transceiver includes a wake-up receiver having an energy-detection based architecture and having circuitry to conduct a counter-based wake up responsive to two pre-specified WiFi compatible packets. A sync receiver is enabled by the wake-up receiver upon reception of the two pre-specified WiFi compatible packets, the sync receiver including circuitry to detect a payload packet and create a backscatter enable signal synced with a payload of the payload packet. A backscatter transmitter is enabled by the backscatter enable signal.

Abstract: termination circuits for backscatter communication in an integrated wake-up receiver tag device. A reflective termination circuit includes a first branch having an open load and a shorted load with first branch offset reflection coefficients and with a connection to an antenna. A second branch has a capacitive load and an inductive load with second branch offset reflection coefficients and with a connection to an antenna. A MIMO termination circuit includes plurality of transmission lines each providing a unique delay that is offset compared to other ones of the plurality of transmission lines. Switched connections to a corresponding array of antennas introduce a delay between a received and backscattered signal at each antenna in the array of antennas.