An analog correlator for ultra-wideband receivers

We present a new analog circuit exhibiting high bandwidth and low distortion, specially designed for signal correlation in an ultra-wideband receiver front end. The ultra-wideband short impulse signals are correlated with a local pulse template by the correlator. A comparator then samples the output for signal detection. A typical Gilbert mixer core is adopted for multiplication of broadband signals up to 10 GHz. As a result of synchronization of the received signal and the local template, the output voltage level after integration and sampling can reach up to 100 mV, which is sufficient for detection by the comparator. The circuit dissipates about 30 mW from double voltage supplies of 4 V and 4.4 V using 0.24 mu m SiGe BiCMOS technology. Simulation results are presented to show the feasibility of this circuit design for use in ultra-wideband receivers.