This Small Business Innovation Research Phase I project aims to develop an indoor real-time locating system to provide a better wireless computer mouse and to enable new 3D human-machine interface. The conventional optical mouse provides only 2D tracking, and requires battery and a non-reflective patterned surface. New human-machine interface based on video processing such as Kinect is limited by line-of-sight and has high demands of CPU cycles on the host computer. This proprietary technology is the passive harmonic RFID tags that can be localized by the reader in sub-millimeter precision within the 2-4 meter reading range, and can provide 9-bit precision of sensor data by multi-frequency phase detection. The main research tasks include 1) conforming the wireless link to the allowable FCC bands of amateur radio, Bluetooth and/or RFID UHF, 2) investigating multi-antenna technology to reduce the multi-path interference in the harmonic uplink, and 3) developing improved algorithms for the mouse motion tracking to minimize the host reader loads. It will formulate the prototype choices for the passive tags as the battery-free 3D mouse and for the dongles on the host Windows computer as the reader. The broader impact is that many other human-machine interfaces for gaming, prosthesis, and motion tracking can be enabled by this RFID technology, which have large market growth potential as well as social impact on everyday life. The plan on the 3D mouse and other human-machine interface such as game controllers will help obtain the necessary manufacturing expertise, grow revenue, and build business reputation. If 10% of the present wireless mouse users would switch to this battery-free, no-surface constraint 3D mouse, the conservative estimate will be a market size at 40 million dollars with one product alone. With further extension of range, multiplexing and digital ID integration, the real-time locating RFID technology will also have broad applications on building energy management, inventory control, and security monitoring. In addition to the conventional harmonic radar concept to reduce interference, several new concepts in the nonlinear-transmission-line based backscattering tags have resulted in self-matched impedance with various antenna, spectrum spilling prevention, high harmonic conversion efficiency, and high-resolution distance determination by preserving the phase information. The enhanced technological understanding of personal area networks will further enable new market applications.
