Crystal-Less RF Communication Integrated Circuits for Wireless Sensor Networks

Over the last two decades, computing device has gone from a laptop to a smartphone and then to a wristwatch-size sensor node. At each step, the volume shrinks by 2-3 orders of magnitude, so does the battery size, while the functionality and computing power remains constant or increases. With thin-film battery technology and CMOS scaling, we can now envision complete sensor nodes with cubic-mm form factors for medical and surveillance applications. In each of these platforms, wireless communication has been essential, and at this scale, wireless maybe the only means of communicating with a contact-less device. As node volume reduces, external components like crystal reference and antenna become the bottleneck of realizing the complete cubic-mm wireless sensor node devices. The thesis covers several aspects of the energy and integration challenges associated with cubic-mm wireless sensor nodes without crystal references. In particular, the goal of the research is to present several new compact and low-power RF circuits for the synchronization and communication of wireless sensor node devices.