Improving interference robustness in ultralow power (ULP) receivers (RXs) is a big challenge due to their low power budget. This paper presents an envelope detector based 915 MHz 10 kb/s ULP RX, which is fabricated in 65 nm CMOS process for wireless sensor networks and Internet of Things. Two power-efficient techniques, transmitted-reference and shifted limiter, are proposed to improve the nterference robustness. The RX sensitivity is between −61 and −76 dBm. The maximum in-band signal-to-interference ratio at ±1 MHz offset is up to −50 dB while just consuming 175 μW power from a 1 V supply.