Patent ID: 8797146
Filing Date: 2014-08-05
Classification: G06K

Abstract:
1. An autonomous battery-free microwave frequency communication device, comprising: a capacitor; at least one antenna; a microwave energy harvesting system which is configured to harvest microwave energy from charging packets received via said at least one antenna and configured to store the microwave energy on said capacitor, wherein the microwave energy harvesting system is configured to transmit a response packet in response to determining that the capacitor is sufficiently charged; a microwave frequency transceiver powered by energy stored on said capacitor, which is configured to use a portion of energy stored on said capacitor to autonomously generate a microwave frequency carrier and to autonomously transmit information using said microwave frequency carrier according to a predetermined communications protocol via said at least one antenna; and a control system powered by energy stored on said capacitor, which is configured to provide said information for transmission, wherein the charging packets comprise wireless local area network (WLAN) protocol beacon frames that are selectively generated for charging the capacitor.