Intelligent tracking system and methods and systems therefor

A passive tracking device comprising:

• a first antenna that transmits first response signals in a first frequency band;
• a second antenna that receives first energizing signals in a second frequency band;
• a third antenna that both transmits second response signals and receives second energizing signals in a third frequency band;
• an energy harvester that receives an energizing signal from a remote device via the second antenna and/or the third antenna and at least partially converts the energizing signal from RF electrical energy to DC electrical energy;
• a clamp circuit that receives the energizing signal from the energy harvester and at least partially converts the energizing signal from the RF electrical energy to the DC electrical energy together with the energy harvester;
• a storage capacitor that receives the DC electrical energy from the clamp circuit and stores the DC electrical energy;
• a voltage regulator that receives the DC electrical energy from one or both of the clamp circuit and the storage capacitor, and regulates voltage of the DC electrical energy;
• a power bus that receives the regulated DC electrical energy from the voltage regulator and energizes the passive tracking device;
• a phase-locked loop that modulates a first response signal for transmission in the first frequency band and outputs the modulated first response signal to the first antenna for transmission when the passive tracking device operates in a first mode in accordance with a first communication protocol, wherein the first response signal includes a first message indicating a first device identifier of the passive tracking device;
• an amplifier that receives the modulated first response signal from the phase-locked loop and amplifies the modulated first response signal for transmission via the first antenna;
• an AC power source that provides signals to the phase-locked loop for modulation;
• a reference oscillator that provides a reference frequency to the AC power source;
• a Gaussian frequency shift keying modulator that works with the phase-locked loop to modulate first response signal;
• a state machine that outputs information to the Gaussian frequency shift keying modulator for inclusion in modulated first response signal;
• a non-volatile memory that stores information that is available for retrieval by the state machine and inclusion in the modulated first response signal;
• a backscatter switch that prepares a second response signal for transmission in the third frequency band and facilitates transmission of the prepared second response signals by toggling impedance of the third antenna when the passive tracking device operates in a second mode in accordance with a second communication protocol, wherein the second response signal includes a second message indicating a second device identifier of the passive tracking device;
• an EPC modem that actuates the backscatter switch to prepare the second response signal;
• and
• a mode selector that receives an energizing signal from the second antenna or the third antenna and determines whether the passive tracking device is to operate in the first mode or the second mode based on the energizing signal.