The need for sustainably powering unobtrusive internet-of-things applications has led to an interest in energy harvesting. Particularly, the proliferation of wireless communication and devices in the 2.4 GHz Industrial Scientific c Medical (ISM) band creates an opportunity to leverage commonly used devices for RF powering. This dissertation presents a low-quiescent-power...
The increasing demand for higher data-rates in spectrum-deficient indoor WiFi networks calls for the adaptation of hybrid systems, consisting of RF and optical wireless channels. The novel hybrid WiFi Free-Space Optical (WIFO) system was introduced to enhance the wireless capacity of indoor WiFi networks. In this thesis, an optical wireless...
In recent years, the research community's interest in fully integrated mm-Wave wireless communication systems has increased significantly. With the standards for 5G NR now in place, the focus has shifted to actual deployment. Mm-Wave systems provide wider bandwidths, higher capacity, and lower latency than existing systems such as 4G. Higher...
Low-power millimeter-wave (mm-wave) transceivers are of interest for achieving energy-efficient high data rate short-reach wireless and guided-wave links.
Spatial modulation or space-shift keying (SSK) can provide energy efficiency improvements by using antenna-switching or transmission direction switching for data modulation. Such links are particularly attractive at millimeter-wave frequencies due to small...
Low-power receivers (RX) with 100$\mu W$-scale power consumption can enable several power/energy-constrained IoT applications. However, achieving sensitivity, interferer tolerance and wide operating range with low power presents a challenge for existing architectures, particularly those constrained to highly integrated solutions without high-Q off-chip components. Existing solutions rely heavily on high quality...
Real time indoor positioning awareness systems aim to add localization capabilities to upcoming wireless technologies that are quickly becoming an important feature for indoor environment. RF-based impulse-radio ultra-wideband (IR-UWB) is a promising technology for in-door positioning systems due to obstacle penetration capabilities, immunity to multi-path and fading, and high resolution....
Ring amplification has emerged as an efficient technique to drive large capacitive loads in switched capacitor circuits. We propose circuit techniques to demonstrate the first application of a ring amplifier in a non-capacitive feedback system of a LDO. These techniques enable a simple cap-less LDO structure in 180nm CMOS that...
Modern sensors are complex systems comprising multiple sub-systems such as transducers, analog and mixed-signal interface circuits, digital processing circuits, and packaging. Over the last few decades, innovations in these sub-systems combined with their increased integration in complementary metal-oxide semiconductor (CMOS) processes have led to the rapid growth in sensors for...
Harvesting energy from ambient sources can provide power autonomy to energy efficient electronics and sensors. The last decade has seen a multitude of ways to scavenge energy from various sources like solar, thermal, electromagnetic, electrostatic, piezo-electric and many more. Thermal energy from human body heat is ubiquitous and can be...
As the CMOS process scales down to submicron, digital circuit performance improves, while reduced supply voltage and lower transistor intrinsic gain make it difficult to implement analog circuits in a power efficient manner. Therefore, it has become advantageous to shift more analog signal processing functions conventionally realized in voltage (analog)...