Patent US5955950A successfully refreshed from Google Patents.
US5955950A
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Low noise signal generator for use with an RFID system
Assignee: Mitsubishi Materials Corp
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Filing: 1998-07-24
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Granted: 1999-09-21
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Expires: 2018-07-24
Abstract
Abstract Noise reduction schemes are provided in a radio frequency identification (RFID) system for use with RFID intelligent tags. Amplitude and phase noise is minimized by starting with a low noise crystal oscillator having an output frequency which is an integer multiple n of the desired RF field frequency, and then dividing this frequency by the integer multiple n. One or more cascaded flip-flops are used for the frequency dividing. Both outputs of the final stage flip-flop are used to drive the transmitter antenna to produce a continuous wave signal.
Inventors
- 👤 William F. Gallagher, III
- 👤 Russell E. Barber
- 👤 Eric Eckstein
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 14:54
CPC Classifications
G; G06; G06K; G06K7/00; G06K7/10; G06K7/10009; G06K7/10316; G06K7/10346; G06K7/0008; G08; G08B; G08B13/00; G08B13/22; G08B13/24; G08B13/2402; G08B13/2405; G08B13/2414; G08B13/2417; G08B13/2465; G08B13/2468; G08B13/2471; G08B13/2474; G08B13/2477
Claims Analysis
Total Claims: 26
Claim 1
Independent Claim
111 words
A signal generator for use in a radio frequency identification (RFID) system, the RFID system having a transmitter antenna assembly with a fundamental field frequency, the transmitter antenna assembly being driven by two input signals having a 180 degree phase difference, the signal generator including: (a) an oscillator having an output frequency which is an integer multiple n of the fundamental field frequency, and (b) a divide by n circuit connected at an input to the oscillator output, the divide by n circuit producing two output signals having a 180 degree phase difference and the same frequency, wherein n≧2, both n-divided output signals being used to drive the transmitter antenna assembly.
Claim 2
Dependent Claim
111 words
A signal generator for use in a radio frequency identification (RFID) system, the RFID system having a transmitter antenna assembly with a fundamental field frequency, the transmitter antenna assembly being driven by two input signals having a 180 degree phase difference, the signal generator including: (a) an oscillator having an output frequency which is an integer multiple n of the fundamental field frequency, and (b) a divide by n circuit connected at an input to the oscillator output, the divide by n circuit producing two output signals having a 180 degree phase difference and the same frequency, wherein n≧2, both n-divided output signals being used to drive the transmitter antenna assembly.
Claim 3
Dependent Claim
37 words
A signal generator according to claim 1 wherein the divide by n circuit comprises at least one flip-flop, the two output signals being the non-phase inverted output and the phase-inverted output of the at least one flip-flop.
Claim 4
Dependent Claim
18 words
A signal generator according to claim 2 wherein n=2, and the divide by n circuit comprises one flip-flop.
Claim 5
Dependent Claim
38 words
A signal generator according to claim 2 wherein n>2 and even, the divide by n circuit comprising n cascaded flip-flops, the two output signals being the non-phase inverted output and the phase-inverted output of the final stage flip-flop.
Claim 6
Dependent Claim
9 words
A signal generator according to claim 1 wherein 16≧n≧2.
Claim 7
Dependent Claim
11 words
A signal generator according to claim 1 wherein n is even.
Claim 8
Independent Claim
103 words
An apparatus for producing at least one drive signal for an interrogator transmitter antenna of a radio frequency identification (RFID) system, the at least one drive signal causing the transmitter antenna to produce a continuous wave signal at a fundamental field frequency, the apparatus comprising a flip-flop which produces at least one output signal at the fundamental field frequency for use as the at least one drive signal, wherein the apparatus produces two drive signals, and the flip-flop produces two output signals having a 180 degree phase difference and the same frequency, the two output signals being used as the two drive signals.
Claim 9
Independent Claim
103 words
An apparatus for producing at least one drive signal for an interrogator transmitter antenna of a radio frequency identification (RFID) system, the at least one drive signal causing the transmitter antenna to produce a continuous wave signal at a fundamental field frequency, the apparatus comprising a flip-flop which produces at least one output signal at the fundamental field frequency for use as the at least one drive signal, wherein the apparatus produces two drive signals, and the flip-flop produces two output signals having a 180 degree phase difference and the same frequency, the two output signals being used as the two drive signals.
Claim 10
Dependent Claim
43 words
An apparatus according to claim 7 further comprising: at least one switched amplifier connected at one end to the transmitter antenna and connected at the other end to the output of the at least one flip-flop for amplifying one of the drive signals.
Claim 11
Dependent Claim
43 words
An apparatus according to claim 7 further comprising: two switched amplifiers, each amplifier being connected at one end to the transmitter antenna and connected at the other end to the output of one of the respective flip-flops for amplifying the two drive signals.
Claim 12
Dependent Claim
237 words
A radio frequency identification (RFID) system having a detection zone, the system detecting the presence of an article in the detection zone wherein the article is tagged with a resonant intelligent tag, the system comprising: (a) a transmitter antenna assembly including a transmitter loop antenna for creating the detection zone, the loop antenna having a predetermined fundamental field frequency and producing a continuous wve signal; (b) a signal generator for driving the transmitter antenna assembly at its fundamental field frequency, the signal generator including: (i) an oscillator having an output frequency which is an integer multiple n of the fundamental field frequency, and (ii) a divide by n circuit connected at an input to the oscillator output for producing at least one output signal, wherein n>2; and (c) an amplifier connected at an input to the divide by n output signal, and connected at an output to the transmitter antenna assembly, the amplifier outputting an n-divided output signal to drive the loop antenna to produce the continuous wave signal, wherein the transmitter antenna assembly is driven by two input signals having a 180 degree phase difference, and the divide by n circuit produces two output signals which have a 180 degree phase difference and the same frequency, the divide by n circuit comprising at least on flip-flop, the two flip-flop output signals being the non-phase inverted output and the phase-inverted output of the at least one flip-flop.
Claim 13
Dependent Claim
237 words
A radio frequency identification (RFID) system having a detection zone, the system detecting the presence of an article in the detection zone wherein the article is tagged with a resonant intelligent tag, the system comprising: (a) a transmitter antenna assembly including a transmitter loop antenna for creating the detection zone, the loop antenna having a predetermined fundamental field frequency and producing a continuous wve signal; (b) a signal generator for driving the transmitter antenna assembly at its fundamental field frequency, the signal generator including: (i) an oscillator having an output frequency which is an integer multiple n of the fundamental field frequency, and (ii) a divide by n circuit connected at an input to the oscillator output for producing at least one output signal, wherein n>2; and (c) an amplifier connected at an input to the divide by n output signal, and connected at an output to the transmitter antenna assembly, the amplifier outputting an n-divided output signal to drive the loop antenna to produce the continuous wave signal, wherein the transmitter antenna assembly is driven by two input signals having a 180 degree phase difference, and the divide by n circuit produces two output signals which have a 180 degree phase difference and the same frequency, the divide by n circuit comprising at least on flip-flop, the two flip-flop output signals being the non-phase inverted output and the phase-inverted output of the at least one flip-flop.
Claim 14
Dependent Claim
18 words
An RFID system according to claim 10 wherein n=2, and the divide by n circuit comprises one flip-flop.
Claim 15
Dependent Claim
190 words
A radio frequency identification (RFID) system having a detection zone, the system detecting the presence of an article in the detection zone wherein the article is tagged with a resonant intelligent tag, the system comprising: (a) a transmitter antenna assembly including a transmitter loop antenna for creating the detection zone, the loop antenna having a predetermined fundamental field frequency and producing a continuous wave signal; (b) a signal generator for driving the transmitter antenna assembly at its fundamental field frequency, the signal generator including: (i) an oscillator having an output frequency which is an integer multiple n of the fundamental field frequency, and (ii) a divide by n circuit connected at an input to the oscillator output for producing at least one output signal, wherein n>2; and (c) an amplifier connected at an input to the divide by n output signal, and connected at an output to the transmitter antenna assembly, the amplifier outputting an n-divided output signal to drive the loop antenna to produce the continuous wave signal, wherein the resonant intelligent tag is a radio frequency identification (RFID) tag, and the fundamental field frequency is a radio frequency.
Claim 16
Dependent Claim
190 words
A radio frequency identification (RFID) system having a detection zone, the system detecting the presence of an article in the detection zone wherein the article is tagged with a resonant intelligent tag, the system comprising: (a) a transmitter antenna assembly including a transmitter loop antenna for creating the detection zone, the loop antenna having a predetermined fundamental field frequency and producing a continuous wave signal; (b) a signal generator for driving the transmitter antenna assembly at its fundamental field frequency, the signal generator including: (i) an oscillator having an output frequency which is an integer multiple n of the fundamental field frequency, and (ii) a divide by n circuit connected at an input to the oscillator output for producing at least one output signal, wherein n>2; and (c) an amplifier connected at an input to the divide by n output signal, and connected at an output to the transmitter antenna assembly, the amplifier outputting an n-divided output signal to drive the loop antenna to produce the continuous wave signal, wherein the resonant intelligent tag is a radio frequency identification (RFID) tag, and the fundamental field frequency is a radio frequency.
Claim 17
Dependent Claim
15 words
An RFID system according to claim 12 wherein the fundamental field frequency is 13.56 MHz.
Claim 18
Dependent Claim
169 words
A radio frequency identification (RFID) system having a detection zone, the system detecting the presence of an article in the detection zone wherein the article is tagged with a resonant intelligent tag, the system comprising: (a) a transmitter antenna assembly including a transmitter loop antenna for creating the detection zone, the loop antenna having a predetermined fundamental field frequency and producing a continuous wave signal; (b) a signal generator for driving the transmitter antenna assembly at its fundamental field frequency, the signal generator including: (i) an oscillator having an output frequency which is an integer multiple n of the fundamental field frequency, and (ii) a divide by n circuit connected at an input to the oscillator output for producing at least one output signal; and (c) an amplifier connected at an input to the divide by n output signal, and connected at an output to the transmitter antenna assembly, the amplifier outputting an n-divided output signal to drive the loop antenna to produce the continuous wave signal, wherein 16≧n≧2.
Claim 19
Dependent Claim
169 words
A radio frequency identification (RFID) system having a detection zone, the system detecting the presence of an article in the detection zone wherein the article is tagged with a resonant intelligent tag, the system comprising: (a) a transmitter antenna assembly including a transmitter loop antenna for creating the detection zone, the loop antenna having a predetermined fundamental field frequency and producing a continuous wave signal; (b) a signal generator for driving the transmitter antenna assembly at its fundamental field frequency, the signal generator including: (i) an oscillator having an output frequency which is an integer multiple n of the fundamental field frequency, and (ii) a divide by n circuit connected at an input to the oscillator output for producing at least one output signal; and (c) an amplifier connected at an input to the divide by n output signal, and connected at an output to the transmitter antenna assembly, the amplifier outputting an n-divided output signal to drive the loop antenna to produce the continuous wave signal, wherein 16≧n≧2.
Claim 20
Dependent Claim
161 words
A radio frequency identification (RFID) system having a detection zone, the system detecting the presence of an article in the detection zone wherein the article is tagged with a resonant intelligent tag, the system comprising: (a) a transmitter antenna assembly including a transmitter loop antenna for creating the detection zone, the loop antenna having a predetermined fundamental field frequency; (b) a signal generator for driving the transmitter antenna assembly at its fundamental field frequency, the signal generator including: (i) an oscillator having an output frequency which is an integer multiple n of the fundamental field frequency, and (ii) a divide by n circuit connected at an input to the oscillator output for producing at least one output signal, wherein n≧2, the divide by n circuit comprising at least one flip-flop, each flip-flop producing a non-phase inverted output and a phase-inverted output, at least one of the non-phase inverted output and the phase-inverted output being used to drive the antenna transmitter assembly.
Claim 21
Dependent Claim
161 words
A radio frequency identification (RFID) system having a detection zone, the system detecting the presence of an article in the detection zone wherein the article is tagged with a resonant intelligent tag, the system comprising: (a) a transmitter antenna assembly including a transmitter loop antenna for creating the detection zone, the loop antenna having a predetermined fundamental field frequency; (b) a signal generator for driving the transmitter antenna assembly at its fundamental field frequency, the signal generator including: (i) an oscillator having an output frequency which is an integer multiple n of the fundamental field frequency, and (ii) a divide by n circuit connected at an input to the oscillator output for producing at least one output signal, wherein n≧2, the divide by n circuit comprising at least one flip-flop, each flip-flop producing a non-phase inverted output and a phase-inverted output, at least one of the non-phase inverted output and the phase-inverted output being used to drive the antenna transmitter assembly.
Claim 22
Dependent Claim
28 words
An RFID system according to claim 15 wherein the resonant intelligent tag is a radio frequency identification (RFID) tag, and the fundamental field frequency is a radio frequency.
Claim 23
Dependent Claim
14 words
An RFID system according to claim 16 wherein fundamental field frequency is 13.56 MHz.
Claim 24
Dependent Claim
24 words
An RFID system according to claim 15 wherein both the phase inverted output and the phase-inverted output used to drive the antenna transmitter assembly.
Claim 25
Dependent Claim
9 words
An RFID system according to claim 15 wherein 16≧n≧2.
Claim 26
Dependent Claim
18 words
An RFID system according to claim 15 wherein n=2, and the divide by n circuit comprises one flip-flop.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2002-09-20 | 2003-03-22 | 2003-09-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2006-09-20 | 2007-03-22 | 2007-09-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2010-09-20 | 2011-03-22 | 2011-09-21 | $7700.00 | Window Closed / Lapsed |