This paper presents a fully integrated UWB-IR transceiver front-end operating in the 7.25-8.5 GHz band designed for high overall transmission and detection energy efficiency and robustness to interferers. The transceiver front-end features a pulsed transmitter that wakes up when triggered by a digital signal, generates a pulse, and automatically switches-off in less than 2 ns. The receiver includes an LNA, a VGA, a squarer, a windowed integrator, and a comparator to perform PPM demodulation of the data. A prototype of the transceiver front-end was integrated in a 0.13 μm CMOS technology. The transmitter delivers 13 pJ/pulse to the antenna consuming about 190 pJ/b, with an efficiency ηT=7%, well in excess of comparable designs. Using pulse polarity scrambling, it complies with the FCC spectral emission limits up to a pulse repetition frequency (PRF) of 5 MHz. The receiver achieves a sensitivity of -87 dBm at a PRF of 100 kHz, and of -70 dBm at a PRF of 5 MHz, while consuming 4.2 mW. It can tolerate interferers up to -12 dBm at 5.4 GHz.