Portable radio frequency emitting identifier

Claim 1

An electronic identification system comprising: a portable identifier having electrical circuits including: an oscillator for generating a constant frequency signal in the radio frequency range; a power source for energizing said circuits; a switching circuit connecting said oscillator to transmit said constant frequency signal; first circuit means for dividing said constant frequency signal down to a lower data cell rate to generate a lower data cell rate signal; means to store a predetermined code representing the identification of said identifier, said code consisting of a first series of bits each of which have the value of one or zero; second circuit means for dividing said data cells of said lower rate signal into equal halves called beginning and ending halves; means to transmit said predetermined code to said switching circuit; means causing said switching circuit to conduct during the beginning data cell half if a code bit is one value and to not conduct if of the other value and means to cause said switching circuit to conduct during the ending data cell half if the code is the other value and not to conduct if it is the one value; means to advance the code through all the bits and thereby cause the switching circuit to conduct and not conduct responsively and thereby generate an identifier signal radiated by said antenna means; an antenna for radiating said identifier signal to points remote to said identifier; a receiver having an antenna to receive said radiated identifier signal and indicate the identity of said identifier by converting said radio frequency signal back to said predetermined code.