US3906402A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Liquid cooled dummy load for RF transmission line
Assignee: Bird Electronic Corp
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Filing: 1974-12-13
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Granted: 1975-09-16
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Expires: 1994-12-13
Abstract
Abstract A liquid cooled dummy load device or termination for an RF coaxial transmission line. Electrical energy is converted to heat energy in a resistive film that is series-connected between the inner and outer conductors of the transmission line and deposited on a tubular cylindrical dielectric substrate. Liquid coolant being circulated through the device to and from a heat exchanger is moved in an axial direction through an inner annular flow passage defined by the inner cylindrical surface of a low friction tube and by the resistive film to absorb the heat energy, then outwardly through radial ports to an outer coaxial annular flow passage defined by the outer cylindrical surface of the aforesaid tube and by the inner surface of another low friction tube and finally to an outlet fitting. The housing has an interior surface form defining an exponential horn chamber surrounding and coaxial with the resistive film to minimize reflection from the device.
Inventors
- 👤 Leo Lesyk
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 14:15
CPC Classifications
H; H01; H01P; H01P1/00; H01P1/24; H01P1/26; H01P1/262
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
284 words
A liquid cooled dummy load device for an RF coaxial transmission line, the device having a connector with first and second contact means for the inner and outer coaxial conductors respectively, and a cylindrical housing; an elongated tubular dielectric member coaxially mounted in said housing, a thin resistive film deposited on the outer surface of said dielectric member and series connected between said first and second contact means, said film being adapted to convert electrical energy being transmitted by said transmission line to heat energy, means defining a liquid inlet, and a liquid outlet at one end of said housing, a first cylindrical sleeve member formed of low friction insulating material surrounding and coaxial with said tubular dielectric member and defining with said thin resistive film an inner annular cylindrical liquid flow passage communicating with said liquid inlet, a second cylindrical sleeve member formed of low friction insulating material surrounding and coaxial with said first cylindrical sleeve member and defining with the outer surface of said first cylindrical sleeve member an outer annular liquid flow passage communicating with said liquid outlet, said second cylindrical sleeve member defining with said housing an exponentIal horn chamber adapted to contain an air medium for minimizing the reflected energy from said termination, means defining radial ports connecting said inner liquid flow passage to said outer liquid flow passage at the ends thereof opposite said inlet and outlet, whereby liquid flowing in said inner flow passage absorbs heat energy from said resistive film, means defining a liquid chamber within said tubular dielectric member and communicating with said liquid inlet to provide a liquid dielectric medium within said tubular dielectric member, and means for pumping cooling liquid through said passages.
Claim 2
Dependent Claim
284 words
A liquid cooled dummy load device for an RF coaxial transmission line, the device having a connector with first and second contact means for the inner and outer coaxial conductors respectively, and a cylindrical housing; an elongated tubular dielectric member coaxially mounted in said housing, a thin resistive film deposited on the outer surface of said dielectric member and series connected between said first and second contact means, said film being adapted to convert electrical energy being transmitted by said transmission line to heat energy, means defining a liquid inlet, and a liquid outlet at one end of said housing, a first cylindrical sleeve member formed of low friction insulating material surrounding and coaxial with said tubular dielectric member and defining with said thin resistive film an inner annular cylindrical liquid flow passage communicating with said liquid inlet, a second cylindrical sleeve member formed of low friction insulating material surrounding and coaxial with said first cylindrical sleeve member and defining with the outer surface of said first cylindrical sleeve member an outer annular liquid flow passage communicating with said liquid outlet, said second cylindrical sleeve member defining with said housing an exponentIal horn chamber adapted to contain an air medium for minimizing the reflected energy from said termination, means defining radial ports connecting said inner liquid flow passage to said outer liquid flow passage at the ends thereof opposite said inlet and outlet, whereby liquid flowing in said inner flow passage absorbs heat energy from said resistive film, means defining a liquid chamber within said tubular dielectric member and communicating with said liquid inlet to provide a liquid dielectric medium within said tubular dielectric member, and means for pumping cooling liquid through said passages.
Claim 3
Dependent Claim
19 words
A device as defined in claim 1 wherein said first and second sleeve members are formed of polytetrafluoro ethylene.
Claim 4
Dependent Claim
44 words
A device as defined in claim 1 wherein said tubular dielectric member defines a radial bleed port at the end thereof opposite said inlet and outlet whereby liquid coolant in said liquid chamber bleeds out into said inner flow passage and is continously replenished.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-09-15 | 1979-03-17 | 1979-09-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-09-15 | 1983-03-17 | 1983-09-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-09-15 | 1987-03-17 | 1987-09-16 | $7700.00 | Window Closed / Lapsed |