Receiving/backscattering arrangement and method with two modulation modes for wireless data transmission as well as modulation arrangement therefor

• US 7,151,436 B2
• Filed: 01/07/2004
• Issued: 12/19/2006
• Est. Priority Date: 01/10/2003
• Status: Active Grant

• Current Assignee: Atmel Corporation (Microchip Technology Incorporated)
• Original Assignee: Atmel Germany GmbH (Microchip Technology Incorporated)
• Inventors: Friedrich, Ulrich, Fischer, Martin
• Primary Examiner(s): Zimmerman, Brian
• Assistant Examiner(s): Brown, Vernal
• Application Number:
  US10/753,859
• Publication Number:
  US 20040145452A1
• Time in Patent Office: 1,077 Days
• Field of Search: 340/10.1, 340/10.2, 340/3.51, 340/505, 340/572.2, 340/572.4, 340/572.5, 340/825.69, 340/825.72, 329/304, 332/103, 332/149, 332/151, 374/324, 374/316, 375/324, 375/316
• US Class Current: 340/10.1
• CPC Class Codes: G06K 19/0723 the record carrier comprising an arrangement for non-contact communication, e.g. wireless communication circuits on transponder cards, non-contact smart cards or RFIDs
• CPC Class Codes: G06K 7/10861 sensing of data fields affixed to objects or articles, e.g. coded labels postal sorting B07C3/14, conveying articles B65G47/48
• CPC Class Codes: H03C 5/00 Amplitude modulation and angle modulation produced simultaneously or at will by the same modulating signal H03C7/00 takes precedence

Abstract

For transmitting data, a receiving/backscattering arrangement receives, modulates and reflects or backscatters electromagnetic waves emitted by a base station. The modulation corresponds to the data to be transmitted and is carried out selectively using first and/or second different modulation methods depending on the received field strength of the received electromagnetic waves. Preferably, phase shift keying is used especially or at least at low field strengths at far range, while amplitude shift keying is used additionally or alternatively for high field strengths at close range. The two modulation methods can be superimposed. A circuit arrangement includes two different modulator arrangements to perform the two modulation methods depending on the received field strength. The second modulator arrangement preferably comprises a multi-stage voltage multiplier circuit with a modulated switching device intervening in one of the stages to achieve the modulation.

Claims

1. A method of wireless data transmission between a base station and a passive receiving/backscattering unit, comprising the steps:

a) emitting electromagnetic waves from said base station;

b) receiving said electromagnetic waves as received waves with said receiving/backscattering unit; and

c) modulating and reflecting said received waves as modulated reflected waves by passive backscattering from said receiving/backscattering unit to said base station, wherein said modulating is carried out in accordance with data that are to be transmitted by said passive backscattering from said receiving/backscattering unit to said base station, and wherein said modulating comprises;

c1) phase shift keying when a received field strength of said received waves is in a first field strength range, and

c2) amplitude shift keying when said received field strength is in a second field strength range higher than said first field strength range,

so as to provide a backscattering distance range of said passive backscattering from said receiving/backscattering unit to said base station that is larger with said phase shift keying than with said amplitude shift keying, and to provide a backscattering transmission quality of said passive backscattering that is higher with said amplitude shift keying than with said phase shift keying.

2. The method of wireless data transmission according to claim 1, wherein said modulating in said step c) comprises performing only said phase shift keying and not said amplitude shift keying when said received field strength is in said first field strength range, and performing both said phase shift keying and said amplitude shift keying superimposed on each other when said received field strength is in said second field strength range.

3. A passive receiving/backscattering arrangement embodied in a passive transponder and adapted to receive electromagnetic waves emitted by a base station and to modulate and reflect said electromagnetic waves by passive backscattering in accordance with data that are to be transmitted by said passive backscattering from said receiving/backscattering arrangement to said base station, wherein said passive receiving/backscattering arrangement comprises:

a first modulator arrangement that comprises a phase shift keying modulator, and that is adapted to modulate said electromagnetic waves by a first modulation comprising a phase shift keying; and

a second modulator arrangement that is different from said first modulator arrangement, and that comprises an amplitude shift keying modulator, and that is adapted to modulate said electromagnetic waves by a second modulation different from said first modulation and comprising an amplitude shift keying;

wherein said first modulator arrangement is activatable selectively in response to a received field strength of said electromagnetic waves received by said receiving/backscattering arrangement being in a first field strength range, and said second modulator arrangement is activatable selectively in response to said received field strength being in a second field strength range higher than said first field strength range, so as to provide a backscattering distance range of said passive backscattering from said receiving/backscattering arrangement to said base station that is larger with said phase shift keying than with said amplitude shift keying, and to provide a backscattering transmission quality of said passive backscattering that is higher with said amplitude shift keying than with said phase shift keying.

4. The receiving/backscattering arrangement according to claim 3, further comprising a rectifier with an output to which said second modulator arrangement is connected.

5. The receiving/backscattering arrangement according to claim 3, wherein said second modulator arrangement comprises a regulator and reference elements connected to said regulator and adapted to provide an adjustable set point value to said regulator.

6. The receiving/backscattering arrangement according to claim 5, wherein said regulator is a voltage regulator and said reference elements comprise zener diodes.

7. The receiving/backscattering arrangement according to claim 3, wherein said second modulator arrangement comprises:

a limiter circuit including plural diodes connected serially in a forward conducting direction between a supply voltage and a reference potential; and

a controllable switching device having a controlled conduction path connected between said reference potential and a junction point between two of said diodes, and having a control input connected to a control line providing a modulation control signal.

8. The receiving/backscattering arrangement according to claim 3, wherein said second modulator arrangement comprises:

plural diodes connected serially in a forward conducting direction between a supply voltage and a reference potential;

a controllable switching device having a controlled conduction path connected between said supply voltage arid said reference potential, and having a control input; and

a logic gate having an output connected to said control input of said controllable switching device, a first input connected to a junction point between two of said diodes, and a second input connected to a control line providing a modulation control signal.

9. The receiving/backscattering arrangement according to claim 8, wherein said logic gate is an AND gate.

10. The receiving/backscattering arrangement according to claim 3, wherein said second modulator arrangement comprises:

plural diodes connected serially in a forward conducting direction between a supply voltage and a reference potential;

a voltage multiplier circuit including plural successive stages;

a controllable switching device having a controlled conduction path connected between a circuit node of one of said stages of said voltage multiplier circuit and said reference potential, and having a control input; and

a logic gate having an output connected to said control input of said controllable switching device, a first input connected to a junction point between two of said diodes, and a second input connected to a control line providing a modulation control signal.

11. The receiving/backscattering arrangement according to claim 10, wherein said logic gate is an AND gate.

12. A modulator arrangement for amplitude shift keying modulation of received electromagnetic waves according to data that are to be transmitted, comprising:

a rectifier including a multistage voltage multiplier circuit having plural successive stages; and

a controllable switching device having a controlled conduction path connected between a circuit node of one of said stages of said voltage multiplier circuit and a reference potential, and having a control input connected to a control line providing a modulation control signal.

13. The modulator arrangement according to claim 12, wherein said circuit node is an output node of said one of said stages.