US4311968A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Magnetron having cavity wall vibrated by tuning fork
Assignee: Teledyne UK Ltd
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Filing: 1979-12-04
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Granted: 1982-01-19
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Expires: 1999-12-04
Abstract
Abstract A co-axial magnetron in which the microwave output frequency can be rapidly altered within a particular frequency band. A movable tuning plate is coupled to a mechanical tuning fork which is set into vibration by an alternating voltage applied to a solenoid.
Inventors
- 👤 Alan H. Pickering
- 👤 Geoffrey J. Rowlands
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 11:22
CPC Classifications
H; H01; H01J; H01J23/00; H01J23/16; H01J23/18; H01J23/20
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
117 words
A co-axial magnetron comprising an evacuated enclosure defining an anode and an annular resonant cavity, said cavity having a longitudinal axis; an elongated cathode positioned within said enclosure and aligned with the longitudinal axis of said cavity; at least one movable conductive plate positioned within said enclosure and forming an end of said cavity; a tuning fork having a pair of arms located within said enclosure, one arm of said tuning fork being ridigly connected to said movable plate to transfer mechanical vibrations to said plate and thereby cyclically alter the resonant frequency of said cavity; and sensor means coupled to said tuning fork for generating a signal corresponding to the instantaneous resonant frequency of said cavity.
Claim 2
Dependent Claim
117 words
A co-axial magnetron comprising an evacuated enclosure defining an anode and an annular resonant cavity, said cavity having a longitudinal axis; an elongated cathode positioned within said enclosure and aligned with the longitudinal axis of said cavity; at least one movable conductive plate positioned within said enclosure and forming an end of said cavity; a tuning fork having a pair of arms located within said enclosure, one arm of said tuning fork being ridigly connected to said movable plate to transfer mechanical vibrations to said plate and thereby cyclically alter the resonant frequency of said cavity; and sensor means coupled to said tuning fork for generating a signal corresponding to the instantaneous resonant frequency of said cavity.
Claim 3
Dependent Claim
31 words
A magnetron as claimed in claim 1 and wherein two movable plates are provided, one at each end of the cavity, with each movable plate being coupled to a tuning fork.
Claim 4
Dependent Claim
28 words
A magnetron as claimed in claim 2 and wherein a single tuning fork is provided with respective ones of its two arms being coupled to each movable plate.
Claim 5
Dependent Claim
27 words
A magnetron as claimed in claim 2 and wherein two tuning forks are provided, one arm of each of which is coupled to a respective movable plate.
Claim 6
Dependent Claim
20 words
A magnetron as claimed in claim 4 and wherein the two tuning forks have mutually different natural frequencies of resonance.
Claim 7
Dependent Claim
41 words
A magnetron as claimed in any of claims 2 to 4 and wherein the tuning fork(s) is maintained in resonance by means of a vibratory drive means, arranged to be driven at the natural frequency of resonance of the tuning fork(s).
Claim 8
Dependent Claim
46 words
A magnetron as claimed in claim 6 and wherein the vibratory drive means forms part of a feedback loop in which said sensor means arranged to sense the mechanical vibrations of the tuning fork is coupled via an adjustable phase shifter to said vibratory drive means.
Claim 9
Dependent Claim
40 words
A magnetron as claimed in claim 6 wherein the vibratory drive means comprises a solenoid, the electromagnetic coil of which is located outside said enclosure and the ferromagnetic member of which is carried by the tuning fork within said enclosure.
Claim 10
Dependent Claim
26 words
A magnetron as claimed in claim 7 wherein said vibratory drive means is arranged to drive the other of the two arms of said tuning fork.
Claim 11
Dependent Claim
107 words
A magnetron including movable conductive means which is movable relative to an annular resonant cavity for determining the frequency of oscillation of a microwave output signal, and characterized by a mechanical resonator in the form of a tuning fork which is located within a vacuum enclosure containing the magnetron anode and said annular resonant cavity, and wherein one arm of said tuning fork is rigidly connected to said movable conductive means so as to vibrate it and thereby to cyclically alter the resonant frequency of the cavity, and means coupled to said tuning fork for generating a signal representative of the instantaneous resonant frequency of the cavity.
Claim 12
Dependent Claim
107 words
A magnetron including movable conductive means which is movable relative to an annular resonant cavity for determining the frequency of oscillation of a microwave output signal, and characterized by a mechanical resonator in the form of a tuning fork which is located within a vacuum enclosure containing the magnetron anode and said annular resonant cavity, and wherein one arm of said tuning fork is rigidly connected to said movable conductive means so as to vibrate it and thereby to cyclically alter the resonant frequency of the cavity, and means coupled to said tuning fork for generating a signal representative of the instantaneous resonant frequency of the cavity.
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) | 1985-01-18 | 1985-07-20 | 1986-01-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1989-01-18 | 1989-07-20 | 1990-01-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1993-01-18 | 1993-07-20 | 1994-01-19 | $7700.00 | Window Closed / Lapsed |