EP0592224A1
Expired / Lapsed
EP
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Dual resonant antenna circuit for RF tags
Assignee: Westinghouse Electric Corp
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Filing: 1993-10-07
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Granted: —
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Expires: 2013-10-07
Abstract
Abstract A two-way communication system is provided having a stationary device and a portable passive device. The portable passive device has circuitry for storing and transmitting coded information. The stationary member transmits a signal at a first frequency via magnetic field and the portable passive device transmits coded information stored on circuitry provided therein at a second frequency also via a magnetic field. An antenna circuit is provided in the portable passive device having a parallel resonant circuit and a series resonant circuit. The parallel resonant circuit derives operating power from the signal at a first frequency for use in the circuitry provided in the portable passive device. The series resonant circuit transmits coded information at a second frequency.
Inventors
- 👤 David Frank Everett
- 👤 Daniel Clifford Buck
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-02 15:41
CPC Classifications
G; G01; G01S; G01S13/00; G01S13/74; G01S13/75; G01S13/751; G01S13/753; G01S13/758; G06; G06K; G06K19/00; G06K19/06; G06K19/067; G06K19/07; G06K19/0723
Claims Analysis
Total Claims: 21
Claim 1
Independent Claim
166 words
In a two-way communication system having a stationary member (22) and a portable passive member (28; 34; 46), said portable passive member (28; 34; 46) having circuitry for storing and transmitting coded information, said stationary member transmitting a signal at a first frequency via a magnetic field and said portable passive member transmitting coded information stored by said circuitry in said portable passive member at a second frequency via a magnetic field, the improvement comprising an antenna circuit provided in said portable passive member (28; 34; 36), said antenna circuit comprising: (a) a parallel resonant circuit (36, 38; 48, 50) for deriving operating power from said signal at a first frequency for use in said circuitry provided in said portable passive member (28; 34; 36); and (b) a series resonant circuit (36, 38, 40; 48, 50, 52) for transmitting at a second frequency said coded information stored by said circuitry in said portable passive member (28; 34; 36), said second frequency differing from said first frequency.
Claim 2
Dependent Claim
38 words
The antenna circuit of claim 1 wherein said parallel resonant circuit comprises a first capacitor (38) in parallel alignment with an inductor coil (36), said inductor coil (36) serving as the antenna for said portable passive member (34).
Claim 3
Dependent Claim
33 words
The antenna circuit of claim 2 wherein said series resonant circuit comprises a second capacitor (40) in serial alignment with the parallel combination of said inductor coil (36) and said first capacitor (38).
Claim 4
Dependent Claim
47 words
The antenna circuit of claim 1 wherein said series resonant circuit comprises a first capacitor (40) in serial alignment with a parallel combination of a second capacitor (38) and an inductor coil (36), said inductor coil (36) serving as the antenna for said portable passive member (34).
Claim 5
Dependent Claim
40 words
The antenna circuit of claim 1 wherein said parallel resonant circuit comprises a capacitor (50) in parallel alignment with a first inductor coil (48), said first inductor coil (48) serving as the receive antenna for said portable passive member (46).
Claim 6
Dependent Claim
50 words
The antenna circuit of claim 5 wherein said series resonant circuit comprises a second inductor coil (52) in serial alignment with the parallel combination of said first inductor coil (48) and said capacitor (50), said second inductor coil (52) serving as a transmit antenna for said portable passive member (46).
Claim 7
Dependent Claim
50 words
The antenna circuit of claim 1 wherein said series resonant circuit comprises a first inductor coil (52) in serial alignment with a parallel combination of a second inductor coil (48) and a capacitor (50), said first inductor coil (52) serving as a transmit antenna for said portable passive member (46).
Claim 8
Dependent Claim
129 words
In a communication system having an active member (22) and at least one passive member (28; 34; 46), said active member (22) transmitting a signal at a first frequency via a magnetic field and said at least one passive member transmitting a signal at a second frequency via a magnetic field, the improvement comprising an antenna circuit provided in said at least one passive member (28; 34; 46), said antenna circuit comprising: (a) a parallel resonant circuit (36, 38; 48, 50) for deriving operating power from said signal at a first frequency for use in said passive member (28; 34; 46); and (b) a series resonant circuit (36, 38, 40; 48, 50, 52) for transmitting said signal at a second frequency, said second frequency differing from said first frequency.
Claim 9
Dependent Claim
40 words
The antenna circuit of claim 8 wherein said parallel resonant circuit comprises a first capacitor (38) in parallel alignment with an inductor coil (36), said inductor coil (36) serving as the antenna for said at least one passive member (34).
Claim 10
Dependent Claim
33 words
The antenna circuit of claim 9 wherein said series resonant circuit comprises a second capacitor (40) in serial alignment with the parallel combination of said inductor coil (36) and said first capacitor (38).
Claim 11
Dependent Claim
49 words
The antenna circuit of claim 8 wherein said series resonant circuit comprises a first capacitor (40) in serial alignment with a parallel combination of a second capacitor (38) and an inductor coil (36), said inductor coil (36) serving as the antenna for said at least one passive member (34).
Claim 12
Dependent Claim
42 words
The antenna circuit of claim 8 wherein said parallel resonant circuit comprises a capacitor (50) in parallel alignment with a first inductor coil (48), said first inductor coil (48) serving as the receive antenna for said at least one passive member (46).
Claim 13
Dependent Claim
51 words
The antenna circuit of claim 12 wherein said series resonant circuit comprises a second inductor coil (52) in serial alignment with the parallel combination of said first inductor coil (48) and said capacitor (50), said second inductor coil serving as a transmit antenna for said at least one passive member (46).
Claim 14
Dependent Claim
52 words
The antenna circuit of claim 8 wherein said series resonant circuit comprises a first inductor coil (52) in serial alignment with a parallel combination of a second inductor coil (48) and a capacitor (50), said first inductor coil (52) serving as a transmit antenna for said at least one passive member (46).
Claim 15
Dependent Claim
131 words
In a two-way communication system having two active members, one of said active members transmitting a signal at a first frequency via a magnetic field and the other of said active members transmitting a signal at a second frequency via a magnetic field, the improvement comprising an antenna circuit provided in each of said active members, said antenna circuit comprising: (a) a parallel resonant circuit (36, 38; 48, 50) for receiving a signal, said parallel resonant circuit being resonant at the frequency of the signal transmitted by the other active member; and (b) a series resonant circuit (36, 38, 40; 48, 50, 52) for transmitting a signal at a frequency differing from said frequency of the received signal, said series resonant circuit being resonant at the frequency of the transmitted signal.
Claim 16
Dependent Claim
37 words
The antenna circuit of claim 15 wherein said parallel resonant circuit comprises a first capacitor (38) in parallel alignment with an inductor coil (36), said inductor coil (36) serving as the antenna for each said active member.
Claim 17
Dependent Claim
33 words
The antenna circuit of claim 16 wherein said series resonant circuit comprises a second capacitor (40) in serial alignment with the parallel combination of said inductor coil (36) and said first capacitor (38).
Claim 18
Dependent Claim
45 words
The antenna circuit of claim 15 wherein said series resonant circuit comprises a first capacitor (40) in serial alignment with a parallel combination of a second capacitor (38) and an inductor coil (36), said inductor coil serving as the antenna for each said active member.
Claim 19
Dependent Claim
39 words
The antenna circuit of claim 15 wherein said parallel resonant circuit comprises a capacitor (50) in parallel alignment with a first inductor coil (48), said first inductor coil (48) serving as the receive antenna for each said active member.
Claim 20
Dependent Claim
49 words
The antenna circuit of claim 19 wherein said series resonant circuit comprises a second inductor coil (52) in serial alignment with the parallel combination of said first inductor coil (48) and said capacitor (50), said second inductor coil (52) serving as a transmit antenna for each said active member.
Claim 21
Dependent Claim
49 words
The antenna circuit of claim 15 wherein said series resonant circuit comprises a first inductor coil (52) in serial alignment with a parallel combination of a second inductor coil (48) and a capacitor (50), said first inductor coil (52) serving as a transmit antenna for each said active member.
References Cited (Backward Citations)
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