Abstract-In this paper, an ultra wideband impulse radio (UWB-IR) transmitter and receiver monolithic microwave integrate circuit (MMIC) for precision localization sensor network is presented. Longer range is achieved with low power consumption at the transmitter by fully exploiting FCC's peak power constraint efficiently. The transmitter and receiver MMIC are fabricated on a commercial low cost 2 μm GaAs HBT process. The transmitter MMIC peak power output is 20 dBm with power consumption of 0.8 mW at 1 MHz pulse repetitive rate. The receiver MMIC uses non-coherent detection and has a 44 dB front-end conversion gain. The receiver MMIC is cascaded with a 500 MHz baseband amplifier to achieve input tangential signal sensitivity (TSS) of - 71 dBm. Equivalent time sampling using analogue to digital converters running at around a few MHz is utilized for precise time of arrival ranging with low cost components. Two dimensional wireless localization network utilizing time difference of arrival (TDOA) is constructed and test results covering an 80 X 90 m2 area show position error variance of less than 10 cm. Ranging at 200 m is demonstrated with range error variance of better than 15 cm.