UWB in Medicine – High Performance UWB Systems for Biomedical Diagnostics and Short Range Communications

The first section describes components for UWB radar sensors and communication systems, namely antennas and integrated circuits. Novel broadband antenna concepts for UWB radar and communication applications are presented. Symmetrical UWB antenna structures for free space propagation with improved performance compared to existing antennas regarding radiation pattern stability over frequency are designed, realized and successfully characterized. Novel differential feeding concepts are applied, suppressing parasitic radiation by cable currents on feed lines. For applications such as communication with implants and catheter localization, a miniaturized antenna optimized for radiation in human tissue is designed. The radiation characteristics of the antenna are measured using an automated setup embedded in a liquid consisting of sugar and water, mimicking the dielectric properties of biological tissue. For UWB radar transmitters, a differential and low-power impulse generator IC is realized addressing the FCC spectral mask based on a quenched cross-coupled LC oscillator. The total power consumption is only 6 mW at an impulse repetition rate of 100MHz. By adding a simple phase control circuit setting the start-up phase condition of the LC oscillator, an impulse generator with a bi-phase modulation scheme is achieved. A further modification introduces a variable width of the pulse envelope as well as a variable oscillation frequency. The corresponding spectra have controllable 10 dB bandwidths and center frequencies fitting the different spectral allocations in the USA, Europe and Japan. On the receiver side, both a fully differential correlation-based and an energy detection receiver for the 3.1-10.6GHz band are designed. Monostatic UWB radar systems require