Integrator and digitizer for a non-coherent IR-UWB receiver

Impulse-radio ultra-wideband systems (IR-UWB) provide short-range wireless communication and precise localization simultaneously. Especially non-coherent IR-UWB reduces the system complexity which enables the design of low-power receivers. This paper presents an integrating digitizer which integrates rectified baseband pulses of an IR-UWB signal and provides the digitized data to the digital baseband of the receiver. The integrator is composed of two time-interleaved (TI) operational amplifiers with capacitive feedback. With this structure, the integrator can be periodically reset without introducing a dead time between two integration periods. The analog-to-digital conversion is performed by a 6 bit 62.4 MS/s successive approximation register analog-to-digital converter (SAR ADC). The integrating digitizer chip is realized in a 250 nm SiGe:C BiCMOS technology from IHP.