Intelligent environments significantly impact human daily lives through embedded sensing and actuating systems. Wireless sensors that can provide non-contact radio information are indispensable. Impulse radar is positioned as a favorable candidate in monitoring and sensing objects [1-3]. The impulse radio is inherently multipath immune and suitable for precision ranging. Accurately detecting signals with low power impulse radios imposes design challenges to impulse radar receivers. In this work, a direct-sampling receiver is proposed and implemented for an impulse radar system. It can support GHz instantaneous bandwidth and more than 100GS/sec equivalent sampling rate through the high-speed sampling circuits and on-chip timing circuitry. The wide bandwidth scattering time-domain waveforms in the radio interaction between the object and radar can be sampled and digitized by the receiver. It achieves precise measurement of time of arrival (TOA) in a radar system and expands the scalability towards antenna arrays for detection of direction of arrival (DOA) .