Dynamic indoor free-space optical communication enabled by beam steering and beam shaping.

Indoor free-space optical communication (FSO) provides orders of magnitude larger usable bandwidth compared to radio-frequency links but suffers from an intrinsic trade-off between areal coverage and received power. In this paper, we report a dynamic indoor FSO system enabled by a line-of-sight optical link featuring advanced beam control capabilities. The optical link herein utilizes a passive target acquisition scheme by combining a beam steering and beam shaping transmitter with a receiver adorned with a ring-shaped retroreflector. When controlled by an efficient beam scanning algorithm, the transmitter is capable of locating the receiver with millimeter-scale accuracy over a distance of 3 m with a full viewing angle of ±11.25∘ in the vertical direction and ±18.75∘ in the horizontal direction within 1.162±0.005s, regardless of the receiver's positions. We also demonstrate 1 Gbit/s data rate with bit error rates below 4×10-7 using an 850 nm laser diode with only 2 mW of output power.

A Passive Wideband Noise-Canceling Mixer-First Architecture With Shared Antenna Interface for Interferer-Tolerant Wake-Up Receivers and Low-Noise Primary Receivers.

Wake-up receivers (WuRX) present an opportunity to reduce average power consumption of IoT transceivers, however achieving sensitivity and interferer tolerance while providing wideband matching and sharing an antenna interface present a significant challenge for existing architectures. This paper presents a primary/WuRX which utilizes a quadrature hybrid coupler based N-Path mixer first architecture to simultaneously achieve low noise, wideband matching and a shared antenna interface. The passive-mixer first approach and a two-code modulated multi-tone signaling scheme provide interferer tolerance in the WuRX. The paper analyzes gain/power trade-offs in the proposed architecture in the context of noise impact with multi-tone WuRX signaling. The proposed architecture is implemented in 65 nm CMOS and occupies 2.25 mm 2. The primary RX achieves 3.8 dB NF and 0.75 dBm out-of-band P1dB with 440µW power consumption. The WuRX achieves -86 dBm sensitivity for 10kb/s data rate and up to -40 dB signal-to-interferer ratio (SIR) with 171µW power consumption.

A 6-Transistor Ultra-Low Power CMOS Voltage Reference with 0.02%/V Line Sensitivity.

This work presents a technique for design of ultra-low power (ULP) CMOS voltage references achieving extremely low line sensitivity while maintaining state-of-the-art temperature insensitivity through the use of a 6-transistor (6T) structure. The proposed technique demonstrates good performance in sub-100 nm CMOS technologies. The 65-nm CMOS implementation occupies only 840 µm2 of area and consumes 28.6 pA from a 0.5 V supply. Measurements from 6 samples from the same wafer show an average line sensitivity of 0.02 %/V, a 10X improvement over previous 65 nm implementations, and an average temperature coefficient of 99.2 ppm/°C.

Wireless Smartphone Control using Electromyography and Automated Gesture Recognition.

In this paper, a wearable, wireless system is demonstrated using electromyography (EMG) signals for realtime control of a smartphone device. The system allows gesturebased control of a smartphone or tablet computer without physical contact, direct line of sight, or significant movement. Additionally, automated gesture detection is shifted to the smartphone, eliminating the need for robust computing hardware. The electronic system and gesture prediction algorithm are described, and measured results are presented and for multiple users. The system demonstrates a maximum true positive detection rate of 92% for a trained user, using three distinct hand gestures. The EMG-based detection system serves as a proof-of-concept for providing wireless, gesture-based control of computer interfaces using low-cost consumer hardware.