Future Wireless Technology
- Single chip CMOS impulse radar
- Continuous-time binary-value (CTBV) processing
- Impulse radio communication
- RF localizati on
- Biomedical applications
The IR-UWB is transmission of short, wideband pulses like Marconi did in the old days of wireless. Unlike carrier modulated transmission of electromagnetic energy emitting strong energy in a narrow spectral band, short pulses or "sparks” emit energy over a wide spectral bandwidth. Due to interference with existing narrowband activity, wideband transmissions have traditionally been prohibited ever since the early days of radio transmission.
However, wideb and wireless transmission has many interesting properties like potentially high transmission bandwidth and interesting propagation properties. When total energy emission is kept low, minor interference is observed with existing narrowband transmissions. When FCC release a 7.5GHz wide band for unlicensed use in 2000, major research efforts were initiated around the world. The released frequency band is the widest bandwidth every released for unlicensed used and is classified as ultra wideband (UWB). An important and demanding restriction is the radiated power is limited to -41.3dBm/MHz (part 15 limit). In fact the part 15 limit is applied for unintentional radiation from any electrical gadget.
Although impulse radio solutions may be promising in many respects, there are profound challenges with interference both from in-band transmission and unintentional radiation. Implementing these systems in standard microelectronics is adding further challenges. At the Nanoelectronics group, Dept. of Informatics we are working with novel CMOS solutions for impulse radio technology and several promising results have emerged.
The Nanoelectronics research group has worked with ultra low power CMOS solutions exploring subthreshold (weak-inversion) operation of MOS devices. Both analog and digital solutions in silicon are reported over the last two decades.