초록 ▼

A transponder system employs a transponder antenna with a distributed inductance and capacitance that exhibit parallel and series resonant frequencies. Transmissions to the transponder circuit are made at one or more parallel resonant frequencies to maximize the excitation of the transponder circuit

A transponder system employs a transponder antenna with a distributed inductance and capacitance that exhibit parallel and series resonant frequencies. Transmissions to the transponder circuit are made at one or more parallel resonant frequencies to maximize the excitation of the transponder circuit, while return signals transmitted back from the transponder are modulated at one or more series resonant frequencies to maximize the signal current. The transponder antenna is implemented as a pair of aligned coils on opposite sides of a thin dielectric substrate, with the coils connected together through the substrate at one point and the substrate thickness not more than about 25 microns to obtain a significant mutual inductance between the coils.

대표청구항 ▼

A transponder communications system, comprising: A) a transponder that includes: a) means for providing a distributed inductance and capacitance with parallel and series resonance at different respective parallel and series resonant frequencies; b) an active return signal generator circuit coupled t

A transponder communications system, comprising: A) a transponder that includes: a) means for providing a distributed inductance and capacitance with parallel and series resonance at different respective parallel and series resonant frequencies; b) an active return signal generator circuit coupled to said inductance and capacitance means, wherein said return signal generator circuit generates and applies to said inductance and capacitance means a return information signal having one of said series resonant frequencies, and c) a power circuit coupled to said inductance and capacitance means and tuned to respond to an actuation signal received by said inductance and capacitance means, said power circuit having one of said parallel resonant frequencies and supplying an energizing signal to said return signal generator circuit; and B) an exciter/reader that includes: a) a transmitter for transmitting said actuation signal to said transponder at one of said parallel resonant frequencies, and b) a receiver for receiving said information signal transmitted from said transponder at said series resonant frequency.