Biologically-Inspired Low-Light Vision Systems for Micro-Air Vehicle Applications

Various insect species such as the Megalopta genalis are able to visually stabilize and navigate at light levels in which individual photo-receptors may receive fewer than ten photons per second. They do so in cluttered forest environments with astonishing success while relying heavily on optic flow estimation. Such capabilities are nowhere near being met with current technology, in large part due to limitations of low-light vision systems. This dissertation presents a body of work that enhances the capabilities of visual sensing in photon-limited environments with an emphasis on low-light optic flow detection. We discuss the design and characterization of two optical sensors fabricated using complementary metal-oxide-semiconductor (CMOS) very large scale integration (VLSI) technology. The first is a frame-based, low-light, photon-counting camera module with which we demonstrate 1-D non-directional optic flow detection with fewer than 100 photons/pixel/frame. The second utilizes adaptive analog circuits to improve room-temperature short-wave infrared sensing capabilities. This work demonstrates a reduction in dark current of nearly two orders of magnitude and an improvement in signal-to-noise ratio of nearly 40dB when compared to similar, non-adaptive circuits. This dissertation also presents a novel simulation-based framework that enables benchmarking of optic flow algorithms in photon-limited environments. Using this framework we compare the performance of traditional optic flow processing algorithms to biologically-inspired algorithms thought to be used by flying insects such as the Megalopta genalis. This work serves to provide an understanding of what may be ultimately possible with optic flow sensors in low-light environments and informs the design of future low-light optic flow hardware

Energy Efficient Wireless Circuits for IoT in CMOS Technology

The demand for efficient and reliable wireless communication equipment is increasing at a rapid pace. The demand and need vary between different technologies including 5G and IoT. The Radio Frequency Integrated Circuits (RFIC) designers face challenges to achieve higher performance with lower power resources. Although advances in Complementary Metal-Oxide-Semiconductor (CMOS) technology has help designers, challenges still exist. Thus, novel and new ideas are welcome in RFIC design. In this dissertation, many ideas are introduced to improve efficiency and linearity for wireless receivers dedicated to IoT applications. A low-power wireless RF receiver for wireless sensor networks (WSN) is introduced. The receiver has improved linearity with incorporated current-mode circuits and high-selectivity filtering. The receiver operates at a 900 MHz industrial, scientific and medical (ISM) band and is implemented in 130 nm CMOS technology. The receiver has a frequency multiplication mixer, which uses a 300 MHz clock from a local oscillator (LO). The local oscillator is implemented using vertical delay cells to reduce power consumption. The receiver conversion gain is 40 dB and the receiver noise figure (NF) is 14 dB. The receiver IIP3 is −6 dBm and the total power consumption is 1.16 mW. A wireless RF receiver system suitable for Internet-of-Things (IoT) applications is presented. The system can simultaneously harvest energy from out-of-band (OB) blockers with normal receiver operation; thus, the battery life for IoT applications can be extended. The system has only a single antenna for simultaneous RF energy harvesting and wireless reception. The receiver is a mixer-first quadrature receiver designed to tolerate large unavoidable blockers. The system is implemented in 180 nm CMOS technology and operates at 900 MHz industrial, scientific and medical (ISM) band. The receiver gain is 41.5 dB. Operating from a 1 V supply, the receiver core consumes 430 µW. This power can be reduced to 220 µW in the presence of a large blocker (≈ 0 dBm) by the power provided by the blocker RF energy harvesting where the power conversion efficiency (PCE) is 30%. Finally, a highly linear energy efficient wireless receiver is introduced. The receiver architecture is a mixer-first receiver with a Voltage Controlled Oscillator (VCO) based amplifier incorporated as baseband amplifier. The receiver benefits from the high linearity of this amplifier. Moreover, novel clock recycling techniques are applied to make use of the amplifier’s VCOs to clock the mixer circuit and to improve power consumption. The system is implemented in 130 nm CMOS technology and operates at 900 MHz ISM band. The receiver conversion gain is 42 dB and the power consumption is 2.9 mW. The out-of-band IIP3 is 6 dBm. All presented systems and circuits in this dissertation are validated and published in various IEEE journals and conferences

Integrated Circuits and Systems for Smart Sensory Applications

Connected intelligent sensing reshapes our society by empowering people with increasing new ways of mutual interactions. As integration technologies keep their scaling roadmap, the horizon of sensory applications is rapidly widening, thanks to myriad light-weight low-power or, in same cases even self-powered, smart devices with high-connectivity capabilities. CMOS integrated circuits technology is the best candidate to supply the required smartness and to pioneer these emerging sensory systems. As a result, new challenges are arising around the design of these integrated circuits and systems for sensory applications in terms of low-power edge computing, power management strategies, low-range wireless communications, integration with sensing devices. In this Special Issue recent advances in application-specific integrated circuits (ASIC) and systems for smart sensory applications in the following five emerging topics: (I) dedicated short-range communications transceivers; (II) digital smart sensors, (III) implantable neural interfaces, (IV) Power Management Strategies in wireless sensor nodes and (V) neuromorphic hardware

Ultrasensitive field-effect biosensors enabled by the unique electronic properties of graphene

Supramolecular & Biomaterials Chemistr