Abstract: An AC powered temperature sensing microchip is powered wirelessly through Resonant Wireless Power Transfer, sends temperature data using backscattering and hence does not require a DC rectifier circuit. It receives the AC power and uses it (without rectifying) to measure the temperature. A Band Gap Reference Oscillator is used to measure the AC signal strength that is received in a microchip and two PTAT oscillators are used to accurately measure the temperature. The outputs of these three oscillators are sent using the backscattering communication method. It can also be used for accurately measuring and communicating the temperature of subject bodies including but not limited to pharmaceutical products such as vaccines, intravenous injections, and other similar medicines. The invention described can also be used for measuring the temperature of food products, blood samples, and any other sensitive product where the continuous monitoring of temperature is a mandatory or regulatory requirement.

Abstract: A set of AC logic circuits that can be powered by AC signals for saving power in microchips. The logic circuits use the relative phases of different AC signals, and a load capacitance to perform digital logic operations in different phases of the AC signals. One phase is used to charge the load capacitor and another phase is used to discharge the capacitor; some of the phases may be just the hold phases to hold the values of the signals. The charging and discharging phases are enabled depending on the input signals and the corresponding expected output of the digital function to be implemented. The circuits can be used in wirelessly powered devices with small number of gates to save power losses associated with the DC rectification. They can be used to perform any kind of combinational gates like NAND, NOR, XOR and also sequential circuits like D Flip flop.