Digel, Johannes; Masini, Michelangelo; Grözing, Markus; Berroth, Manfred (Institute of Electrical and Optical Communications Engineering, University of Stuttgart, Germany)
Fischer, Gunter; Olonbayar, Sonom; Gustat, Hans; Scheytt, Johann-Christoph (IHP, Frankfurt (Oder), Germany)
A voltage integrator which is followed by a successive approximation register (SAR) analog-to-digital converter (ADC) for an impulse-radio (IR) ultra-wideband (UWB) receiver is presented in this paper. A sequence of wideband impulses carries information in IR-UWB systems which are used for short-range wireless communication and localization. The radio frequency (RF) frontend provides baseband impulses to the input of the proposed circuit. The first stage is an integrator that senses the impulses. Its output voltage depends on the number of received impulses and is converted to a digital code. The sequence of codes is passed to a digital processor that is able to retrieve the transmitted data. The integrating analog-to-digital converter operates with a sampling frequency of 62.4 MS/s i.e. the integration period is about 16 ns. The core consumes 16.2 mA from a 2.6 V supply. The integrated circuit is fabricated in the 250 nm SiGe BiCMOS technology SGB25V from IHP.