Future wireless sensor networks require reliable, batteryless, miniaturized, low-cost sensor nodes with ultralow power consumption. Remote RF powering provides a reliable wireless power source for such monolithically integrated sensor nodes. Combining highly integrated ultralow power millimeter-wave (mm-wave) sensing, wireless power transfer, and on-chip antenna is a path toward batteryless, fully monolithically integrated, millimeter-sized sensor nodes with only a few milligrams of weight. In this paper, a passive fully integrated monolithic wireless sensor for mm-wave sensing is presented in a 65-nm CMOS technology, including an on-chip wireless power receiver, on-chip antenna, and a low-power transmitter