Modeling, design and simulation of low complexity IR-UWB transceiver for medical monitoring applications

This paper presents the system architecture, modeling, design constraints and simulations for an integrated impulse radio ultra-wideband IEEE 802.15.4a transceiver intended for a wearable medical devices for monitoring vital signal parameters. The system design constraints are quantified and dealt off against implementation options with a strong focus on reducing complexity and power consumption. The radio supports low data rates of 110 kbps and ranging capabilities over short distances. The pulse generator which is the most important block in a multiband UWB transmitter is based on the modified triangular pulse shape and it is implemented as a set of four of pulse generators in parallel, allowing the data to be clocked at 125MHz. Simulations show an output pulses with a duration of 4.76ns, which corresponds to 423 MHz bandwidth. The simulated Transmitter has peak output amplitude of 1V, transmitted power of -13.77dBm, a noise figure of 8.3dB, a cascade gain of 18.52dB. The output spectrum centered at 3.4944, 3.9936 and 4.4928 GHz, respectively fully complies with the FCC spectral mask and the rectangular channel mask with more than 30dB of side lobes suppression without the need of additional filter. Receivers performances like noise figure, gain, IIP3, P_-1dB are simulated and optimized to meet receiver specifications. The receiver simulations show 104.8dB conversion gain, -18 dBm IIP3,-27.3 dBm P-_1dB, 15 dB return loss (S11), 5.34 dB NF and -86.18 sensitivity.