| The thesis presents system level and block level integrated circuit solutions for low power wirelessly powered passive sensors, specically biomedical implants and RFID systems.;Wirelessly-powered battery-less sensors extract the required energy from external radiators. As such, their sensitivity is very low. The concept of dynamic energy storage is introduced enabling an extended operation of battery-less systems wirelessly powered. Millimeter-wave power harvesting can lead to a self-contained, CMOS-only system, since the antenna size can be reduced to enable on-chip integration. However, as frequency increases, the RF-to-DC power conversion eciency decreases. One possible solution for mm-wave power harvesting which may result in a more efficient system is to have an efficient battery-less frequency downconversion scheme followed with an efficient low-frequency rectier. A novel passive subharmonic generation and frequency downconversion method, using a memory-less nonlinear circuit coupled to a linear passive resonator, is presented to transfer the energy from a high frequency signal to a lower frequency without requiring any DC power supply.;Advancements in the Micro-Electro-Mechanical Systems (MEMS) and integrated electronics enable implantable systems for various health-care applications. Neural recording systems are one of the important bioimplant devices, since they can enable accurate study of brain neurological activities, as well as creating neuroprosthetics devices to help the disabled people. Neural implants have stringent requirements on the power and area consumption. In order to reduce the energy consumption, a new event-driven scheme is proposed. |
