Battery-powered RF signaling system and system for controlling the whereabouts of an animal using same

Abstract

A system apparatus for controlling the whereabouts of an animal includes a receiver/stimulator unit affixed to the animal to selectively administer appropriate aversive stimuli effective to deter the animal from encroachment of boundaries in accordance with predetermined conditions based on radio signals received from at least one battery powered transmitter. The system may receive radio signals intermittently transmitted from the transmitter, the radio signals defining at least one boundary for the animal. The system then selectively administers the appropriate aversive stimuli in response to determining that at least one of the received radio signals satisfies one or more of the predetermined conditions.

What is claimed is:  
     
         1 . A radio frequency (RF) signaling system, comprising: 
 (a) a battery;    (b) a resonant circuit coupled to said battery, said resonant circuit being resonant substantially at an RF carrier frequency, said resonant circuit including an antenna and deriving operating energy only from said battery; and    (c) a drive circuit coupled to said battery and said resonant circuit, said drive circuit deriving operating energy only from said battery and delivering to said resonant circuit, at substantially said RF carrier frequency, brief pulses of electrical energy separated by intervals of time in order to cause said resonant circuit to resonate, thereby exciting said antenna to transmit an RF signal at substantially said RF carrier frequency.    
     
     
         2 . The system of    claim 1    wherein said drive circuit comprises a circuit which delivers said pulses of electrical energy at a duty cycle of less than about one percent (1%).  
     
     
         3 . The system of    claim 1    wherein said drive circuit comprises a circuit which delivers said pulses of electrical energy at a duty cycle of less than about five percent (5%).  
     
     
         4 . The system of    claim 1    wherein said drive circuit comprises a circuit which delivers said pulses of electrical energy at a duty cycle of less than about fifteen percent (15%).  
     
     
         5 . The system of    claim 1    wherein said antenna is electrically small and said RF carrier frequency is a frequency of about ten kilohertz or less.  
     
     
         6 . The system of    claim 1    wherein said RF signal comprises a signal having a magnetic field whose magnitude decreases substantially in proportion to the cube of increasing distance from said antenna.  
     
     
         7 . The system of    claim 1    wherein said apparatus further comprises circuitry for controlling the phase of said pulses to digitally encode said RF signal.  
     
     
         8 . The system of    claim 1    wherein said RF signal comprises a signal having an amplitude bounded by an envelope having a substantially constant magnitude.  
     
     
         9 . The system of    claim 1    further comprising an isolation circuit operably interposed between said drive circuit and said resonant circuit, said isolation circuit, said isolation circuit effectively electrically isolating said drive circuit from said resonant circuit during at least a portion of said intervals whereby loading effects of said drive circuit on said resonant circuit are reduced, efficiency of said transmitter increased and useful life of said battery prolonged.  
     
     
         10 . A system for controlling the whereabouts of an animal, said system comprising: 
 (a) a battery;    (b) a transmitter coupled to said battery said transmitter transmitting at predetermined intervals radio frequency (RF) signals defining a boundary for the animal said transmitter deriving all energy required for operating said transmitter only from said battery;    (c) a receiver from receiving said signals; and    (d) a stimulator operably coupled to said receiver for administering at least one stimulus to the animal to deter the animal from encroachment of said boundary in response to determining, based on said RF signals, whether at least one predetermined condition indicating encroachment of said boundary has been satisfied.    
     
     
         11 . The system of    claim 10    wherein said predetermined condition comprises reception of at least one of said RF signals during a predetermined window of time.  
     
     
         12 . The system of    claim 11    wherein said window of time is a window of time occurring subsequent to reception of a previously transmitted one of said RF signals.  
     
     
         13 . The system of    claim 10    wherein said transmitter includes: 
 (a) a resonant circuit which includes a resonant circuit resonant substantially at an RF carrier frequency, said resonant circuit including an antenna, and;  
 (b) a drive circuit which delivers to said resonant circuit at substantially said RF carrier frequency, pulses of electrical energy separated by intervals of time so as to cause said antenna to intermittently transmit said RF signal at substantially said RF carrier frequency.  
 
     
     
         14 . The system of    claim 12    further comprising an isolation circuit operably interposed between said drive circuit and said resonant circuit, said isolation circuit effectively electrically isolating said drive circuit from said resonant circuit during at least a portion of said intervals whereby loading effects of said drive circuit on said resonant circuit are reduced efficiency of said transmitter increased and useful life of said battery prolonged.  
     
     
         15 . The system of    claim 10    wherein said RF signal comprises a signal having an amplitude bounded by an envelope of substantially constant magnitude.