US5883575A
Expired / Lapsed
US
⏱️ 0.0 years remaining
RF-tags utilizing thin film bulk wave acoustic resonators
Assignee: Avago Technologies International Sales Pte Ltd
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Filing: 1997-08-12
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Granted: 1999-03-16
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Expires: 2017-08-12
Abstract
Abstract An RF tag having an antenna for receiving a RF signal having a frequency band between first and second frequencies and an acoustical resonator having a resonant frequency related to the first and second frequencies. The acoustical resonator has first and second electrodes that sandwich a layer of piezoelectric material. The antenna is connected to one of these electrodes. The resonator filters the signal received on the antenna. The filter can function either as a notch filter or as a bandpass filter. A resonator that acts as a bandpass filter includes a third electrode and a second layer piezoelectric material sandwiched between the second electrode and the third electrode. A frequency multiplier circuit may be incorporated in the RF tag to provide a response signal that occupies a frequency band at a frequency above the second frequency. In one embodiment of the present invention, multiple resonators having different resonant frequencies are utilized to generate a response code. In one embodiment of the present invention, the resonators are suspended on a support member over a substrate at locations on the support member which differ in thickness.
Inventors
- 👤 Richard C. Ruby
- 👤 Philip Canfield
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 16:45
CPC Classifications
H; H03; H03H; H03H9/00; H03H9/46; H03H9/54; H03H9/58; H03H9/582; H03H9/583; H03H9/585; G; G08; G08B; G08B13/00; G08B13/22; G08B13/24; G08B13/2402; G08B13/2405; G08B13/2414; G08B13/2417; G08B13/2422; G08B13/2428; G08B13/2431; G08B13/2437; G08B13/2442; H03H9/15; H03H9/17; H03H9/171; H03H9/586
Claims Analysis
Total Claims: 18
Claim 1
Independent Claim
80 words
An RF tag comprising: an antenna for receiving a RF signal having a frequency band between first and second frequencies; and a first acoustical resonator comprising a first electrode, a second electrode, and a first layer of piezoelectric material sandwiched between said first and second electrodes, said resonator having a resonant frequency F, said antenna being connected to one of said electrodes, said first acoustical resonator modifying said received RF signal, said modified RF signal being re-transmitted by said antenna.
Claim 2
Dependent Claim
80 words
An RF tag comprising: an antenna for receiving a RF signal having a frequency band between first and second frequencies; and a first acoustical resonator comprising a first electrode, a second electrode, and a first layer of piezoelectric material sandwiched between said first and second electrodes, said resonator having a resonant frequency F, said antenna being connected to one of said electrodes, said first acoustical resonator modifying said received RF signal, said modified RF signal being re-transmitted by said antenna.
Claim 3
Dependent Claim
15 words
The RF tag of claim 1 wherein F is between said first and second frequencies.
Claim 4
Dependent Claim
49 words
The RF tag of claim 1 further comprising: a second acoustical resonator, comprising a first electrode, a second electrode, and a layer of piezoelectric material sandwiched between said first and second electrodes, said second resonator having a resonant frequency different from said resonant frequency of said first acoustical resonator.
Claim 5
Dependent Claim
21 words
The RF tag of claim 3 further comprising a selective coupling circuit for connecting said second acoustical resonator to said antenna.
Claim 6
Dependent Claim
89 words
An RF tag comprising: an antenna for receiving a RF signal having a frequency band between first and second frequencies; a first acoustical resonator comprising a first electrode a second electrode and a first layer of piezoelectric material sandwiched between said first and second electrodes, said resonator having a resonant frequency F, said antenna being connected to one of said electrodes and a frequency doubling circuit, wherein said first acoustical resonator forms a bandpass filter having a pass-frequency at F, and wherein F is greater than said second frequency.
Claim 7
Dependent Claim
89 words
An RF tag comprising: an antenna for receiving a RF signal having a frequency band between first and second frequencies; a first acoustical resonator comprising a first electrode a second electrode and a first layer of piezoelectric material sandwiched between said first and second electrodes, said resonator having a resonant frequency F, said antenna being connected to one of said electrodes and a frequency doubling circuit, wherein said first acoustical resonator forms a bandpass filter having a pass-frequency at F, and wherein F is greater than said second frequency.
Claim 8
Dependent Claim
35 words
The RF tag of claim 5 further comprising a low-pass filter having a cut-off frequency greater than said second frequency but less than F, said low-pass filter connecting said antenna to said frequency doubling circuit.
Claim 9
Dependent Claim
21 words
The RF tag of claim 5 wherein said bandpass filter alters the phase of a signal having frequency F passing therethrough.
Claim 10
Dependent Claim
70 words
The RF tag of claim 7 further comprising: a second acoustical resonator, comprising a first electrode, a second electrode, and a layer of piezoelectric material sandwiched between said first and second electrodes, said second resonator forming a second bandpass filter having a pass-band, said second bandpass filter altering the phase of a signal in said pass-band by an amount different from the phase alteration provided by said first band-pass filter.
Claim 11
Dependent Claim
85 words
An RF tag comprising: an antenna for receiving a RF signal having a frequency band between first and second frequencies; a first acoustical resonator comprising a first electrode, a second electrode and a first layer of piezoelectric material sandwiched between said first and second electrodes, said resonator having a resonant frequency F, said antenna being connected to one of said electrodes and a frequency doubling circuit connected to one of said electrodes of said acoustical resonator and wherein F is greater than said second frequency.
Claim 12
Dependent Claim
85 words
An RF tag comprising: an antenna for receiving a RF signal having a frequency band between first and second frequencies; a first acoustical resonator comprising a first electrode, a second electrode and a first layer of piezoelectric material sandwiched between said first and second electrodes, said resonator having a resonant frequency F, said antenna being connected to one of said electrodes and a frequency doubling circuit connected to one of said electrodes of said acoustical resonator and wherein F is greater than said second frequency.
Claim 13
Dependent Claim
16 words
The RF tag of claim 9 wherein said frequency doubling circuit comprises a zero bias diode.
Claim 14
Dependent Claim
126 words
An RF tag comprising: an antenna for receiving a RF signal having a frequency band between first and second frequencies: a first acoustical resonator comprising a first electrode, a second electrode, and a first layer of piezoelectric material sandwiched between said first and second electrodes, said resonator having a resonant frequency F, said antenna being connected to one of said electrodes; a second acoustical resonator, comprising a first electrode, a second electrode, and a layer of piezoelectric material sandwiched between said first and second electrodes, said second resonator having a resonant frequency different from said resonant frequency of said first acoustical resonator and a support member having a variable thickness, said first and second resonators being supported on said support member at locations having different thickness.
Claim 15
Dependent Claim
126 words
An RF tag comprising: an antenna for receiving a RF signal having a frequency band between first and second frequencies: a first acoustical resonator comprising a first electrode, a second electrode, and a first layer of piezoelectric material sandwiched between said first and second electrodes, said resonator having a resonant frequency F, said antenna being connected to one of said electrodes; a second acoustical resonator, comprising a first electrode, a second electrode, and a layer of piezoelectric material sandwiched between said first and second electrodes, said second resonator having a resonant frequency different from said resonant frequency of said first acoustical resonator and a support member having a variable thickness, said first and second resonators being supported on said support member at locations having different thickness.
Claim 16
Dependent Claim
132 words
An RF tag comprising: an antenna for receiving a RF signal having a frequency band between first and second frequencies; a first acoustical resonator comprising a first electrode, a second electrode, and a first layer of piezoelectric material sandwiched between said first and second electrodes, said resonator having a resonant frequency F, said antenna being connected to one of said electrodes; a second acoustical resonator, comprising a first electrode, second electrode, and a layer of piezoelectric material sandwiched between said first and second electrodes; and a membrane, said first acoustical resonator contacting said membrane at a first location on said membrane and said second acoustical resonator contacting said membrane at a second location on said membrane, wherein said membrane has a different thickness at said first location than at said second location.
Claim 17
Dependent Claim
132 words
An RF tag comprising: an antenna for receiving a RF signal having a frequency band between first and second frequencies; a first acoustical resonator comprising a first electrode, a second electrode, and a first layer of piezoelectric material sandwiched between said first and second electrodes, said resonator having a resonant frequency F, said antenna being connected to one of said electrodes; a second acoustical resonator, comprising a first electrode, second electrode, and a layer of piezoelectric material sandwiched between said first and second electrodes; and a membrane, said first acoustical resonator contacting said membrane at a first location on said membrane and said second acoustical resonator contacting said membrane at a second location on said membrane, wherein said membrane has a different thickness at said first location than at said second location.
Claim 18
Dependent Claim
47 words
The RF tag of claim 12 further comprising a substrate and a support column, said membrane being suspended over said substrate and said support column contacting said substrate and said membrane, said contact with said membrane being located at a point between said first and second locations.
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| 3.5 Years (Year 4) | 2002-03-15 | 2002-09-14 | 2003-03-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2006-03-15 | 2006-09-14 | 2007-03-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2010-03-15 | 2010-09-14 | 2011-03-16 | $7700.00 | Window Closed / Lapsed |