A pinboard by
Kurt Schab

Postdoc, North Carolina State University


The smaller an antenna gets, the worse it performs; can we get around this by playing clever tricks?

An antenna is the critical part of any wireless communication device which transmits and receives electromagnetic (e.g., radio) waves. For over half a century, engineers and physicists have asked the question: what is the “best” antenna possible for a given wireless system? Mathematically this question is a tough one to solve, but over the years various researchers have arrived at key results known as fundamental antenna bounds. For wireless systems with small antennas (mobile phones, small Internet of Things devices), the results from these bounds aren't good. As an antenna becomes smaller, several performance parameters important for maintaining a good wireless data link become irretrievably poor. This degradation with decreasing size suggests there exists a hard limit of how fast and efficiently small devices can send and receive data. So are small devices doomed to run up against their fundamental limit as expectations for portable high-data-rate wireless applications (streaming high-definition video, wireless virtual reality, video calling) continue to increase year after year?

My research approaches this problem by studying the assumptions under which the fundamental bounds on antenna performance were derived. In most cases, these assumptions are based on how radios and antennas have been built since the earliest days of wireless communications. By critically examining these assumptions, we can find conditions under which the fundamental bounds no longer hold. Then by identifying and exploiting these conditions, we can design new kinds of antenna and radio architectures which are totally unlike the status quo and which are no longer hindered by the fundamental bounds. This work covers fundamental theoretical problems associated with the physics of small antennas, it explores performance implications of different design strategies used to break the fundamental bounds, and it includes construction and field assessment of prototypes to demonstrate the validity of very unconventional yet potentially groundbreaking antenna systems.