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US3748592A Expired / Lapsed US ⏱️ 0.0 years remaining

Magnetron oscillators

Assignee: Teledyne UK Ltd
•
Filing: 1972-05-04
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Granted: 1973-07-24
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Expires: 1992-05-04
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Abstract

Abstract A magnetron oscillator having the normally provided cavities of a magnetron oscillator, has a further resonant cavity coupled to one of the normally provided cavities by an inductive loop. The further cavity is provided with two electrodes facing one another, the opposing faces being coated with a secondary electron emissive material. The two electrodes are spaced apart such that an electron released from one surface takes a time equal to half a cycle of the R.F. voltage developed between the two electrodes to cross the gap to the other electrode thereby producing a multipactor discharge between the two electrodes. While multipactor discharging occurs the further cavity is effectively short circuited so that the magnetron frequency of oscillation is the resonant frequency of its anode cathode resonator. The multipactor discharge is stopped by application of a D.C. voltage to the two electrodes so that the further cavity pulls the magnetron frequency.

Inventors

  • 👤 A Pickering

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-09 09:30
CPC Classifications
H; H03; H03C; H03C3/00; H03C3/30; H03C3/32; H03B; H03B9/00; H03B9/01; H03B9/10

Claims Analysis

Total Claims: 10
Claim 1
Independent Claim 128 words
A magnetron oscillator selectively tunable to a first and a second oscillating frequency comprising a cathode and anode structure having a plurality of cavities therein; a separate resonant cavity coupled to one of said cavities in the cathode and anode structure so as to determine the oscillating frequency of said magnetron oscillator; a pair of spaced electrodes within said separate cavity each electrode having a surface facing the other electrode, each surface formed of secondary electron emissive material, and the spacing between the two electrodes being suitably dimensioned to enable a multipactor discharge to be initiated and sustained between said electrodes so as to cause the oscillator to oscillate at said first frequency; and means for extinguishing said multipactor discharge whereby the oscillator oscillates at said second frequency.
Claim 2
Dependent Claim 128 words
A magnetron oscillator selectively tunable to a first and a second oscillating frequency comprising a cathode and anode structure having a plurality of cavities therein; a separate resonant cavity coupled to one of said cavities in the cathode and anode structure so as to determine the oscillating frequency of said magnetron oscillator; a pair of spaced electrodes within said separate cavity each electrode having a surface facing the other electrode, each surface formed of secondary electron emissive material, and the spacing between the two electrodes being suitably dimensioned to enable a multipactor discharge to be initiated and sustained between said electrodes so as to cause the oscillator to oscillate at said first frequency; and means for extinguishing said multipactor discharge whereby the oscillator oscillates at said second frequency.
Claim 3
Dependent Claim 45 words
A magnetron oscillator according to claim 1 wherein said means for extinguishing comprises means for applying a voltage to said electrodes whereby a d.c. voltage may be applied during operation to effect inhibition or switching off of a multipactor discharge set up between the electrodes.
Claim 4
Dependent Claim 27 words
A magnetron oscillator according to claim 2 wherein said separate cavity is formed on the outer wall of the cathode and anode structure of the magnetron oscillator.
Claim 5
Dependent Claim 27 words
A magnetron oscillator according to claim 3 wherein said separate cavity is coupled to one of the cavities in the cathode anode structure by a coupling loop.
Claim 6
Dependent Claim 17 words
A magnetron oscillator according to claim 4 wherein one of said electrodes is provided with a heater.
Claim 7
Dependent Claim 129 words
A magnetron oscillator selectively tunable to a first oscillating frequency and to a second oscillating frequency, said oscillator comprising in combination: magnetron anode-cathode resonator means for normally resonating at a frequency near to said first oscillating frequency, said resonator means including a magnetron resonant cavity; a separate resonant cavity capable of causing said resonator means to oscillate at said second oscillating frequency; coupling means coupling said magnetron resonant cavity to said separate resonant cavity for causing said oscillator preferentially to oscillate at said second selected frequency; multipactor discharge means in said separate resonant cavity for effectively short circuiting said separate resonant cavity whereby said oscillator oscillates at said first oscillating frequency; and means for selectively controlling said multipactor discharge means to select the frequency at which said oscillator osCillates.
Claim 8
Dependent Claim 129 words
A magnetron oscillator selectively tunable to a first oscillating frequency and to a second oscillating frequency, said oscillator comprising in combination: magnetron anode-cathode resonator means for normally resonating at a frequency near to said first oscillating frequency, said resonator means including a magnetron resonant cavity; a separate resonant cavity capable of causing said resonator means to oscillate at said second oscillating frequency; coupling means coupling said magnetron resonant cavity to said separate resonant cavity for causing said oscillator preferentially to oscillate at said second selected frequency; multipactor discharge means in said separate resonant cavity for effectively short circuiting said separate resonant cavity whereby said oscillator oscillates at said first oscillating frequency; and means for selectively controlling said multipactor discharge means to select the frequency at which said oscillator osCillates.
Claim 9
Dependent Claim 44 words
A magnetron oscillator as defined in claim 6 wherein said multipactor discharge means comprises spaced electrodes between which multipactor discharge tends to occur at said second oscillating frequency due to the magnitude of energy coupled to said separate resonant cavity by said coupling means.
Claim 10
Dependent Claim 34 words
A magnetron oscillator as defined in claim 7 wherein said means for selectively controlling said multipactor discharge means comprises means for selectively applying a dc voltage to said electrodes to extinguish multipactor discharge therebetween.

References Cited (Backward Citations)

US2674694A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1976-07-23 1977-01-22 1977-07-24 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1980-07-23 1981-01-22 1981-07-24 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1984-07-23 1985-01-22 1985-07-24 $7700.00 Window Closed / Lapsed

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