Embedding data on a power signal

Abstract

Disclosed are various embodiments for embedding data on a guided surface wave. A guided surface waveguide probe emits power as a guided surface wave received by a guided surface wave receive structure circuit. An aggregate electric load of the receiver circuit is modulated with reference to a data signal. A current at the guided surface waveguide probe is monitored. A data signal is recaptured at the guided surface waveguide probe.

Therefore, the following is claimed: 
     
         1 . A method comprising:
 transmitting electrical energy in a form of a guided Zenneck surface wave along a surface of a lossy conducting medium using a guided surface waveguide probe by exciting at least one resultant electric field that synthesizes a wave front incident at a complex Brewster angle of incidence to the lossy conducting medium;   detecting a modulation in current at the guided surface waveguide probe; and   sampling the current to obtain an embedded symbol.   
     
     
         2 . The method of  claim 1 , wherein the current is sampled to detect different amplitude levels that correspond to different binary digits of the embedded symbol. 
     
     
         3 . The method of  claim 1 , wherein the current is sampled to detect different phase levels that correspond to different binary digits of the embedded symbol. 
     
     
         4 . The method of  claim 1 , wherein the current is sampled to detect different frequency levels that correspond to different binary digits of the embedded symbol. 
     
     
         5 . The method of  claim 1 , wherein the modulation in the current is at or above a predefined frequency, the method further comprising filtering the current at the guided surface waveguide probe to remove current flow below the predefined frequency. 
     
     
         6 . The method of  claim 1 , further comprising coupling an ammeter to the guided surface waveguide probe and the lossy conducting medium, wherein the ammeter is used to detect the modulation in the current at the guided surface waveguide probe. 
     
     
         7 . The method of  claim 1 , further comprising:
 elevating a charge terminal to a height above the lossy conducting medium; and   electrically coupling at least one section of internal coil to an excitation source, wherein the guided surface waveguide probe comprises the charge terminal and the internal coil.   
     
     
         8 . The method of  claim 7 , further comprising electrically coupling a feed network to the charge terminal, the feed network providing a phase delay that matches a wave tilt angle associated with the complex Brewster angle of incidence. 
     
     
         9 . The method of  claim 1 , wherein the wave front incident is synthesized at a distance from the guided surface waveguide probe greater than or equal to a Hankel crossover distance at a frequency of operation to cause the guided Zenneck surface wave to be launched in the lossy conducting medium. 
     
     
         10 . The method of  claim 1 , further comprising:
 receiving electrical energy from the guided Zenneck surface wave transmitted by the guided surface waveguide probe; and   embedding a symbol in the current at the guided surface waveguide probe by modulating the current.   
     
     
         11 . A system comprising:
 a guided surface waveguide probe configured to transmit electrical energy in a form of a guided Zenneck surface wave along a surface of a lossy conducting medium by exciting at least one resultant electric field that synthesizes a wave front incident at a complex Brewster angle of incidence to the lossy conducting medium;   an ammeter coupled to the guided surface waveguide probe, wherein the ammeter is configured to observe a current at the guided surface waveguide probe; and   demodulation circuitry coupled to the ammeter, wherein the demodulation circuitry is configured to detect a modulation in current at the guided surface waveguide probe and sample the current to obtain an embedded symbol.   
     
     
         12 . The system of  claim 11 , wherein the demodulation circuitry is configured to sample the current to detect different amplitude levels that correspond to different binary digits of the embedded symbol. 
     
     
         13 . The system of  claim 11 , wherein the demodulation circuitry is configured to sample the current to detect different phase levels that correspond to different binary digits of the embedded symbol. 
     
     
         14 . The system of  claim 11 , wherein the demodulation circuitry is configured to sample the current to detect different frequency levels that correspond to different binary digits of the embedded symbol. 
     
     
         15 . The system of  claim 11 , wherein the modulation in the current is at or above a predefined frequency, the system further comprising a filter coupled to the ammeter that is configured to remove current flow below the predefined frequency. 
     
     
         16 . The system of  claim 11 , wherein the guided surface waveguide probe comprises a charge terminal elevated to a height above the lossy conducting medium; and at least one section of internal coil electrically coupled to an excitation source. 
     
     
         17 . The system of  claim 16 , further comprising a feed network electrically coupled to the charge terminal, the feed network providing a phase delay that matches a wave tilt angle associated with the complex Brewster angle of incidence. 
     
     
         18 . The system of  claim 11 , wherein the wave front incident is configured to be synthesized at a distance from the guided surface waveguide probe greater than or equal to a Hankel crossover distance at a frequency of operation to cause the guided Zenneck surface wave to be launched in the lossy conducting medium. 
     
     
         19 . The system of  claim 11 , further comprising:
 a guided surface wave receive structure that is configured to obtain electrical energy from the guided Zenneck surface wave transmitted by the guided surface waveguide probe; and   modulation circuitry configured to embed a symbol in the current at the guided surface waveguide probe by modulating the current.   
     
     
         20 . The system of  claim 19 , wherein the modulation circuitry modulates the current by varying an impedance of an electrical load coupled to the guided Zenneck surface wave receive structure.