Project Overview

Ultra-Low-Power Wireless Transmitter with Passive Bragg Oscillator

# 0725688
Edwin Kan (Principal Investigator)

Intellectual Merits: The proposed effort seeks to make a fundamental breakthrough in realizing the ultra-low-power wireless transmitter for low-bit-rate communication in millimeter-size systems. In conventional radio link, the small antenna size constrained by the overall system geometry will require high carrier frequency, but a lower limit of the power consumption will be set by the parasitic capacitance of the radio circuits. There are several previous efforts to resolve this basic conflict, including an extended dormant mode, ultra-wide-band pulse systems, and the carrier-based impulse radio. However, either the physical antenna is difficult to realize, or the power can not be sufficiently reduced. The proposed transmitter requires only a narrow-band antenna, but generates the carrier oscillation from a passive Bragg lattice. The digital base band is operated at a low frequency close to the specified bit rate of communication, and can be readily implemented in the digital wrist watch fashion. The signal rise and fall time can be first sharpened by a buffer, and then be further sharpened with enlarged magnitude in nonlinear transmission lines. When the wave front contains a large signal with characteristic frequency exceeding the Bragg lattice frequency, single-tone oscillating waves are generated with high power conversion efficiency to drive the millimeter-size antenna.

Broader Impacts: Inexpensive millimeter-size autonomous systems have many important applications such as environmental monitoring, body implants for disease screening and detection with minimal intrusion, the creation of intelligent spaces, and structural health monitoring. The key missing technology is the low-power wireless link. The success of this research effort will bring forth major impacts on senor network and biomedical implants. The miniature autonomous system design will also serve as the main example for outreach to high-school female and minority students to boost their aptitude towards engineering as a socially relevant career direction.

Source: NSF