UC Berkeley

Recently, there has been an increasing push to make everything wireless. In contrast to high-performance cellular communication, where the demand for enormous quantities of data is skyrocketing, these small wireless sensor and actuator nodes require low power, low cost, and a high degree of system integration. A typical CMOS system-on-chip requires a number of off-chip components for proper operation, namely, a crystal oscillator to act as an accurate frequency reference, and an antenna. The primary goal of this thesis is to address the hurdles associated with operating without these components at as low a power level as possible. This is a step towards the ubiquitous presence of wireless communication.

In this work, an evaluation of transceiver performance is performed with power, performance, and physical size in mind. Operation of a low-power standards compatible 2.4 GHz transmitter (TX) is demonstrated without the use of an off-chip frequency reference. These 2.4 GHz transceivers (TRX), called the single chip motes, operate at low power levels without an off-chip frequency reference. The first single chip mote demonstrated RF chip-to-chip communication in the presence of local oscillator drift caused by temperature variation. It used a free-running LC tank oscillator that was calibrated against drift with periodic network traffic. The next single chip mote was a 2.4 GHz, 802.15.4 TRX, BLE advertising TX system-on-chip with integrated digital baseband and a Cortex M0. Once again, the chip uses no off-chip frequency reference. Finally, a design of high frequency transceiver with integrated antenna is presented, paving the way for a fully on-chip solution.