Brian Otis

Circuit Techniques for Ultra-Low Power Radios

As low power radio circuits are enabling new technology avenues such as health monitoring, efforts to tackle the design challenge of making extremely reliable yet lost cost, low power CMOS radios have gained prominence. Despite advancements in battery technology and energy harvesting, there remains a wide gap between the available and desired performance. Innovative system architectures and circuits need to be explored to bridge this gap. Over the last few years, there have been numerous sub-mW integrated system offerings that trade off performance and reliability to achieve low power consumption. At the same time, an ever growing list of applications has led to a number of commercial products that guarantee robust operation with power consumption in 10′s of mWs. However, a vast number of applications demand sub-mW power consumption or complete energy autonomy while demanding robust operation and high performance over a highly variable environment. Implantable systems are a prime example of this. In this chapter, we will begin with an overview of system considerations, application driven challenges, and proceed to discuss the existing design approaches to make the reader aware of the practical limitations of many of these techniques. We will then identify the fundamental design challenges and explore fresh angles to approach the problem.