System and Method for Communicating with an Unpowered Device

Abstract

An apparatus for performing operations using low power, including control circuitry; a radio frequency (RF) circuit for receiving RF signals at one or more frequencies; an internal power source; and switching circuitry coupled between the control circuitry and the internal power source, the switching circuitry having a control terminal coupled to an output of the RF circuit. The apparatus is configured in a normal mode of operation and an off mode of operation in which the apparatus is powered down, and wherein in the off mode of operation energy from the received RF signals control a state of the switching circuitry to selectively couple the internal power source with the control circuitry for performing one or more operations.

What is claimed is: 
     
         1 . An apparatus, comprising:
 processing circuitry;   a radio frequency (RF) circuit for receiving RF signals at one or more frequencies;   an internal power source; and   switching circuitry coupled between the processing circuitry and the internal power source, the switching circuitry having a control terminal coupled to an output of the RF circuit such that energy from the received RF signals control a state of the switching circuitry to selectively couple the internal power source with the processing circuitry for performing one or more operations while a remainder of the apparatus is unpowered.   
     
     
         2 . The apparatus of  claim 1 , wherein the processing circuitry comprises a processor and memory coupled thereto. 
     
     
         3 . The apparatus of  claim 1 , wherein when the internal power source is coupled to the processing circuitry, at least one of the received RF signals communicates at least one of an instruction and data to the processing circuitry for performing the one or more operations. 
     
     
         4 . The apparatus of  claim 3 , wherein the RF circuit comprises a first antenna for receiving RF signals at a first range of frequencies for controlling the state of the switching circuitry and a second antenna for receiving RF signals at a second range of frequencies for communicating the at least one of the instruction and data with the processing circuitry. 
     
     
         5 . The apparatus of  claim 1 , wherein the RF signals comprise new program code and the apparatus further comprises memory having stored therein stored program code, wherein the one or more operations comprises replacing the stored program code with the new program code. 
     
     
         6 . The apparatus of  claim 1 , wherein the processing circuitry includes an output signal coupled to the control terminal of the switching circuitry. 
     
     
         7 . The apparatus of  claim 4 , wherein the processing circuitry, when coupled to the internal power source, selectively controls the state of the switching circuitry to decouple the internal power source from the processing circuitry. 
     
     
         8 . The apparatus of  claim 1 , wherein the internal power source comprises a battery. 
     
     
         9 . The apparatus of  claim 1 , wherein the internal power source comprises a capacitive member and the capacitive member comprises a first plate coupled to the RF circuit such that the received RF signals charge the capacitive member. 
     
     
         10 . The apparatus of  claim 1 , wherein the internal power source supplies power only to the processing circuitry. 
     
     
         11 . The apparatus of  claim 1 , wherein the processing circuitry authenticates a source of the received RF signals prior to performing the one or more operations. 
     
     
         12 . The apparatus of  claim 1 , wherein the RF circuit includes an RF transmitter and the one or more operations includes an upload operation in which data is transmitted by the RF transmitter. 
     
     
         13 . An apparatus, comprising:
 control circuitry;   a radio frequency (RF) circuit for receiving RF signals at one or more frequencies;   an internal power source; and   switching circuitry coupled between the control circuitry and the internal power source, the switching circuitry having a control terminal coupled to an output of the RF circuit;   wherein the apparatus is configured in a normal mode of operation and an off mode of operation in which the apparatus is powered down, and wherein in the off mode of operation energy from the received RF signals control a state of the switching circuitry to selectively couple the internal power source with the control circuitry for performing one or more operations.   
     
     
         14 . The apparatus of  claim 13 , wherein the RF circuit is coupled to the control circuitry such that at least one of a command and data is communicated between the RF circuit and the control circuitry during the time the switching circuitry couples the internal power source to the control circuitry. 
     
     
         15 . The apparatus of  claim 14 , further comprising memory, wherein the one or more operations comprises a download operation in which at least one of data and program code executable by the apparatus is downloaded to the memory. 
     
     
         16 . The apparatus of  claim 14 , wherein the RF circuit comprises an RF transmitter, and the one or more operations comprises an upload operation in which at least one of data and an instruction from the apparatus is transmitted by the RF transmitter. 
     
     
         17 . The apparatus of  claim 14 , wherein the RF circuit comprises a first antenna for receiving RF signals at a first range of frequencies to control the state of the switching circuitry and a second antenna for receiving RF signals at a second range of frequencies to communicate with the control circuitry. 
     
     
         18 . The apparatus of  claim 13 , wherein the control circuitry comprises a processor and memory coupled thereto. 
     
     
         19 . The apparatus of  claim 13 , wherein the control circuitry, when coupled to the internal power source, selectively controls the state of the switching circuitry to decouple the internal power source from the control circuitry. 
     
     
         20 . The apparatus of  claim 13 , wherein the control circuitry authenticates a source of the received RF signals prior to performing the one or more operations.