US5994984A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Wireless signal distribution in a building HVAC system
Assignee: Carnegie Mellon University
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Filing: 1998-05-29
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Granted: 1999-11-30
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Expires: 2018-05-29
Abstract
Abstract The present invention is directed to a system for using the ductwork of a building for transmitting electromagnetic radiation. The system includes a device for introducing electromagnetic radiation into the ductwork such that the ductwork acts as a waveguide for the electromagnetic radiation. The system also includes a bi-directional coupler positioned to re-radiate the electromagnetic radiation around an obstacle. The system further includes a device for enabling the electromagnetic radiation to propagate beyond the ductwork. The present invention is also directed to a method for transmitting electromagnetic radiation using the ductwork of a building and a method for designing a system for transmitting electromagnetic radiation in the ductwork of a building.
Inventors
- 👤 Daniel D. Stancil
- 👤 Christopher P. Diehl
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 07:40
CPC Classifications
H; H01; H01Q; H01Q21/00; H01Q21/0006; H01Q21/0037; H01Q21/0043; H01Q21/005; H01P; H01P3/00; H01P3/12; H01Q1/00; H01Q1/007
Claims Analysis
Total Claims: 28
Claim 1
Independent Claim
63 words
A system for using the ductwork of a building for transmitting electromagnetic radiation, comprising: a device for introducing electromagnetic radiation into the ductwork such that the ductwork acts as a waveguide for the electromagnetic radiation; a bi-directional coupler positioned to re-radiate the electromagnetic radiation around an obstacle in the ductwork; and a device for enabling the electromagnetic radiation to propagate beyond the ductwork.
Claim 2
Independent Claim
63 words
A system for using the ductwork of a building for transmitting electromagnetic radiation, comprising: a device for introducing electromagnetic radiation into the ductwork such that the ductwork acts as a waveguide for the electromagnetic radiation; a bi-directional coupler positioned to re-radiate the electromagnetic radiation around an obstacle in the ductwork; and a device for enabling the electromagnetic radiation to propagate beyond the ductwork.
Claim 3
Dependent Claim
16 words
The system of claim 1 wherein said device for introducing includes a coaxial to waveguide probe.
Claim 4
Dependent Claim
13 words
The system of claim 1 wherein said device for introducing includes an antenna.
Claim 5
Dependent Claim
14 words
The system of claim 1 wherein said device for enabling includes a coupler probe.
Claim 6
Dependent Claim
15 words
The system of claim 1 wherein said device for enabling includes an electrically transparent louver.
Claim 7
Dependent Claim
13 words
The system of claim 1 wherein said bi-directional coupler includes a bi-directional amplifier.
Claim 8
Dependent Claim
39 words
The system of claim 1 further comprising an electrically opaque reflector located at a point in the ductwork where the ductwork changes direction, said reflector for reflecting the electromagnetic radiation in a direction following the direction of the ductwork.
Claim 9
Dependent Claim
12 words
The system of claim 7 wherein said reflector is a metal sheet.
Claim 10
Dependent Claim
12 words
The system of claim 7 wherein said reflector is a wire grid.
Claim 11
Dependent Claim
22 words
The system of claim 1 further comprising a wire screen ground plane located in the ductwork adjacent to said device for introducing.
Claim 12
Dependent Claim
24 words
The system of claim 1 further comprising an electrically translucent damper located in the ductwork, said damper for deflecting air flow in the ductwork.
Claim 13
Dependent Claim
23 words
The system of claim 1 further comprising an absorber located in the ductwork, said absorber for minimizing multiple reflections of said electromagnetic radiation.
Claim 14
Dependent Claim
25 words
The system of claim 1 wherein said device for enabling includes at least one dielectric member, said member located in a slot in the ductwork.
Claim 15
Independent Claim
61 words
A system for distributing electromagnetic radiation through a building, comprising: at least one HVAC duct; means for introducing the electromagnetic radiation into said duct such that said duct acts as a waveguide for the electromagnetic radiation; bi-directional coupler means for re-radiating the electromagnetic radiation around an obstacle in said duct; and means for enabling the electromagnetic radiation to exit said duct.
Claim 16
Independent Claim
61 words
A system for distributing electromagnetic radiation through a building, comprising: at least one HVAC duct; means for introducing the electromagnetic radiation into said duct such that said duct acts as a waveguide for the electromagnetic radiation; bi-directional coupler means for re-radiating the electromagnetic radiation around an obstacle in said duct; and means for enabling the electromagnetic radiation to exit said duct.
Claim 17
Independent Claim
59 words
A method for transmitting electromagnetic radiation using the ductwork of a building, comprising the steps of: introducing the electromagnetic radiation into the ductwork such that the ductwork acts as a waveguide for the electromagnetic radiation; re-radiating the electromagnetic radiation in a plurality of directions around an obstacle in the ductwork; and enabling the electromagnetic radiation to exit the ductwork.
Claim 18
Independent Claim
59 words
A method for transmitting electromagnetic radiation using the ductwork of a building, comprising the steps of: introducing the electromagnetic radiation into the ductwork such that the ductwork acts as a waveguide for the electromagnetic radiation; re-radiating the electromagnetic radiation in a plurality of directions around an obstacle in the ductwork; and enabling the electromagnetic radiation to exit the ductwork.
Claim 19
Dependent Claim
25 words
The method of claim 15 further comprising the step of reflecting the electromagnetic radiation in a direction following a change in direction of the ductwork.
Claim 20
Dependent Claim
23 words
The method of claim 15 further comprising the step of grounding portions of the ductwork to impede the transmission of the electromagnetic radiation.
Claim 21
Dependent Claim
29 words
The method of claim 15 further comprising the step of matching the impedance of the ductwork to the impedance of an electromagnetic radiation transmitter used for said introducing step.
Claim 22
Independent Claim
60 words
A system for transmitting electromagnetic radiation in a heating, ventilation, and air conditioning duct, comprising: a transmitter located in the duct, said transmitter for transmitting the radiation; a bi-directional amplifier located in the duct, said amplifier for re-radiating the electromagnetic radiation around an obstacle in the duct; and a receiver located in the duct, said receiver for receiving the radiation.
Claim 23
Independent Claim
60 words
A system for transmitting electromagnetic radiation in a heating, ventilation, and air conditioning duct, comprising: a transmitter located in the duct, said transmitter for transmitting the radiation; a bi-directional amplifier located in the duct, said amplifier for re-radiating the electromagnetic radiation around an obstacle in the duct; and a receiver located in the duct, said receiver for receiving the radiation.
Claim 24
Dependent Claim
21 words
The method of claim 19 further comprising a second transmitter located in the duct, said second transmitter for transmitting the radiation.
Claim 25
Independent Claim
44 words
A method for transmitting electromagnetic radiation in a heating, ventilation, and air conditioning duct, comprising the steps of: transmitting the electromagnetic radiation in the duct; and passing the electromagnetic radiation outside of the duct through slots in the duct filled with a dielectric material.
Claim 26
Independent Claim
44 words
A method for transmitting electromagnetic radiation in a heating, ventilation, and air conditioning duct, comprising the steps of: transmitting the electromagnetic radiation in the duct; and passing the electromagnetic radiation outside of the duct through slots in the duct filled with a dielectric material.
Claim 27
Independent Claim
51 words
A system for transmitting electromagnetic radiation in a heating, ventilation, and air conditioning duct, comprising: a transmitter located in the duct, said transmitter for transmitting the electromagnetic radiation; and at least one dielectric member covering a slot in the duct, said member for transmitting the electromagnetic radiation outside of the duct.
Claim 28
Independent Claim
51 words
A system for transmitting electromagnetic radiation in a heating, ventilation, and air conditioning duct, comprising: a transmitter located in the duct, said transmitter for transmitting the electromagnetic radiation; and at least one dielectric member covering a slot in the duct, said member for transmitting the electromagnetic radiation outside of the duct.
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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) | 2002-11-29 | 2003-05-31 | 2003-11-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2006-11-29 | 2007-05-31 | 2007-11-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2010-11-29 | 2011-05-31 | 2011-11-30 | $7700.00 | Window Closed / Lapsed |