Method and apparatus for generating an equipment reply signal for the automatic identification of objects and/or living beings

• US 4,418,411 A
• Filed: 03/10/1981
• Issued: 11/29/1983
• Est. Priority Date: 03/11/1980
• Status: Expired due to Fees

• Current Assignee: Brown Boveri & CIE AG (ABB Limited)
• Original Assignee: Brown Boveri & CIE AG (ABB Limited)
• Inventors: Strietzel, Rainer
• Primary Examiner(s): Malzahn, David H.
• Application Number:
  US06/242,177
• Time in Patent Office: 994 Days
• Field of Search: 371/67, 340/146.3 K, 340/825.34
• US Class Current: 714/819
• CPC Class Codes: G01S 13/78 discriminating between different kinds of targets, e.g. IFF-radar, i.e. identification of friend or foe G01S13/75, G01S13/79 take precedence
• CPC Class Codes: G06K 7/0008 General problems related to the reading of electronic memory record carriers, independent of its reading method, e.g. power transfer
• CPC Class Codes: G07C 9/28 the pass enabling tracking or indicating presence

Abstract

Method and apparatus for generating an equipment reply signal for the automatic identification of objects and/or living beings, including a stationary interrogator having an energy transmitter, a receiver, an evaluator connected to the receiver, an opening code generator, and a first modulator connected to the energy transmitter, and a transponder fastened to the object or living being having a circuit unit with an energy receiver and converter, a code memory, a clock generator, a code transmitter, at least one antenna, an opening code receiver, an opening code memory, an opening code comparator connected to the opening code memory and the opening code receiver, a demodulator connected to the energy receiver and converter, and a second modulator connected to the demodulator, code transmitter, opening code transmitter and code memory, which includes radiating an opening code in the interrogator, storing the opening code in the transponder, radiating a code stored in the code memory by the code transmitter if the stored and radiated opening codes coincide, modulating a reply carrier signal on an energy wave with the first modulator, separating the reply carrier signal from the energy wave with the demodulator, modulating the reply signal carrier with the code with the second modulator, and radiating the modulated reply carrier signal as the reply signal with the code transmitter.

Claims

1. Method for generating an equipment reply signal for the automatic identification of objects and/or living beings, including a stationary interrogator having an energy transmitter, a receiver, an evaluator connectedto the receiver, an opening code generator, and a first modulator connected to the energy transmitter, and a transponder fastened to the object or living being having a circuit unit with an energy receiver and converter, a code memory, a clock generator, a code transmitter, at least one antenna, an opening code receiver, an opening code memory, an opening code comparator connected to the opening code memory and the opening code receiver, a demodulator connected to the energy receiver and converter, and a second modulator connected to the demodulator, code transmitter, opening code comparator and code memory, which comprises radiating opening codes in the interrogator, transmitting the radiated opening codes from the interrogator to the transponder, radiating a code stored in the code memory by the code transmitter if the opening code stored in the opening code memory of the transponder and the radiated opening codes transmitted from the interrogator to the transponder coincide, modulating a reply carrier signal on an energy wave with the first modulator of the interrogator, transmitting the modulated energy wave with the energy transmitter of the interrogator to the energy receiver and converter of the transponder, separating the reply carrier signal from the energy wave with the demodulator of the transponder, modulating the reply carrier signal with the code with the second modulator in the transponder, and transmitting the modulated reply carrier signal as a reply signal with the code transmitter.

2. Method according to claim 1, wherein the step of modulating the energy wave with the reply carrier signal is carried out by amplitude modulating.

3. Method according to claim 1, wherein the step of modulating the energy wave with the reply carrier signal is carried out by frequency modulating.

4. Method according to claim 3, wherein the demodulator is a flank demodulator.

5. Method according to claim 1, which includes doubling the frequency of the reply carrier signal in the interrogator before the reply carrier signal is transmitted to the transponder by the energy transmitter

6. Method according to claim 1, which includes amplitude modulating the reply carrier signal with the code stored in the code memory with the second modulator of the transponder connected to the code memory and the code transmitter of the transponder.

7. Method according to claim 1, which includes modulating the reply carrier signal with the opening code signal in the interrogator.

8. Method according to claim 7, which includes pulse width modulating the reply carrier signal.

9. Method according to claim 1, wherein the interrogator includes a reply carrier signal generator connected to the first modulator, a heterodyne signal generator connected to the reply carrier signal generator, and a demodulator connected betweeen the heterodyne signal generator and the receiver, which includes forming a heterodyned signal with the heterodyne signal generator of the interrogator from a reply carrier signal generated by the reply carrier signal generator of the interrogator, and demodulating the reply signal received by the receiver from the code transmitter of the transponder in the demodulator of the interrogator with the heterodyned signal, before feeding the reply signal to the evaluator of the interrogator.

10. Apparatus for generating an equipment reply signal for the automatic identification of objects and/or living beings, comprising a stationary interrogator having an energy transmitter, a code receiver, an evaluator connected to said code receiver, an opening code generator, an opening code transmitter connected to said opening code generator, a reply carrier signal generator for generating a reply carrier signal, and an energy modulator connected between said reply carrier signal generator and said energy transmitter for modulating an energy wave to be radiated by said energy transmitter with the reply carrier signal, and a transponder being fastened to the object or living being and having a circuit unit with an energy receiver and converter, a code memory, a clock generator, a code transmitter connected to said code memory, at least one antenna connected to said energy receiver and converter, an opening code receiver, an opening code memory, an opening code comparator connected to said opening code memory and to said opening code receive, an opening code processor connected in series with said opening code comparator, a code modulator being connected to said code memory and being connected between said code transmitter and said opening code processor, a demodulator connected to said energy receiver and converter, and a reply carrier signal filter connected in series with said code modulator and being connected between said demodulator and code transmitter, said code transmitter being operable to radiate a code stored in said code memory if the opening code radiated by said interrogator and the opening code stored in said transponder coincide.

11. Apparatus according to claim 10, including a heterodyne signal generator in said interrogator connected to said reply carrier signal generator in the interrogator for generating a heterodyned signal from the reply carrier signal, and a demodulator in the interrogator connected to said code receiver and heterodyne signal generator for demodulating the reply signal with the heterodyne signal.

12. Apparatus according to claim 10 or 11, including a further modulator connected to said reply carrier signal generator and opening code generator in said interrogator for modulating an output signal of said opening code generator on the reply carrier signal before the reply carrier signal is modulated on the energy wave, and an opening code demodulator in the transponder connected to said first-mentioned demodulator and to said reply carrier filter in the transponder for separating the opening code from the reply carrier signal.

13. Apparatus according to claim 12, wherein said further modulator is a pulse width modulator.

14. Apparatus according to claim 10, wherein said first-mentioned energy modulator and code modulator are amplitude modulators.

15. Apparatus according to claim 10, wherein said opening code transmitter and energy transmitter are combined into a single unit in said interrogator.

16. Apparatus according to claim 10, wherein said energy receiver and converter and said opening code receiver are combined into a single unit in said transponder.