US3919666A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Solid state microwave cavity oscillator operating below cavity cutoff frequency
Assignee: MA Com Inc
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Filing: 1974-11-26
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Granted: 1975-11-11
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Expires: 1994-11-26
Abstract
Abstract A microwave oscillator using a Gunn diode in a section of rectangular waveguide tuned to resonate as a cavity to a fundamental frequency that is below the waveguide cutoff frequency has its output for the fundamental frequency located at a place in the cavity at which a peak of the fundamental frequency wave and a null of the second harmonic coincide. Fundamental frequency output is taken in a direction transverse to the axis of the waveguide. Harmonic frequency energy can also be taken from the waveguide section, or suppressed, as desired.
Inventors
- 👤 Ronald Sheldon Posner
- 👤 Richard Marion Walker
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 06:44
CPC Classifications
H; H03; H03B; H03B9/00; H03B9/12; H03B9/14; H03B9/145; H03B2009/126; H03B2200/00; H03B2200/006; H03B2200/007; H03B2201/00; H03B2201/01; H03B2201/014; H03B2201/015
Claims Analysis
Total Claims: 20
Claim 1
Independent Claim
208 words
An electronic oscillator for providing electromagnetic wave energy at microwave frequencies, comprising a section of transmission line having a longitudinal axis, an electron discharge device which is capable of generating such energy in a range of frequencies including a fundamental frequency fO which is below the cut-off frequency of said transmission line, and a harmonic frequency of fO which propagates in a single mode in said transmission line, means coupling said device to a first region in said transmission line section, tuning means in a second region of the transmission line section spaced a known distance along said axis from said first region for tuning a portion of said section including said first and second regions to resonate substantially as a half-wave cavity to said fundamental frequency fO, means selected from one or both of (a) means to suppress generation of said harmonic frequency and (b) means to establish in said line a standing wave of said harmonic frequency having a null in the vicinity of a peak of the fundamental frequency wave, and output means to extract energy at said fundamental frequency fO from said portion of said transmission line section, for supplying said fundamental frequency energy substantially free of said harmonic energy to a receiver therefor.
Claim 2
Dependent Claim
208 words
An electronic oscillator for providing electromagnetic wave energy at microwave frequencies, comprising a section of transmission line having a longitudinal axis, an electron discharge device which is capable of generating such energy in a range of frequencies including a fundamental frequency fO which is below the cut-off frequency of said transmission line, and a harmonic frequency of fO which propagates in a single mode in said transmission line, means coupling said device to a first region in said transmission line section, tuning means in a second region of the transmission line section spaced a known distance along said axis from said first region for tuning a portion of said section including said first and second regions to resonate substantially as a half-wave cavity to said fundamental frequency fO, means selected from one or both of (a) means to suppress generation of said harmonic frequency and (b) means to establish in said line a standing wave of said harmonic frequency having a null in the vicinity of a peak of the fundamental frequency wave, and output means to extract energy at said fundamental frequency fO from said portion of said transmission line section, for supplying said fundamental frequency energy substantially free of said harmonic energy to a receiver therefor.
Claim 3
Dependent Claim
30 words
An oscillator according to claim 1 wherein said cavity resonates also as a cavity n half-wavelengths long to the second harmonic 2fO, where n is an integer greater than 1.
Claim 4
Dependent Claim
32 words
An oscillator according to claim 1 including means to extract from said transmission line electromagnetic wave energy at a frequency above said cut-off frequency which is a harmonic of said fundamental frequency.
Claim 5
Dependent Claim
62 words
An oscillator according to claim 1 including means located in a third region of the transmission line on the opposite side of said second region from said first region, for establishing effectively a short circuit at said harmonic frequency, the distance between said third region and said output means being an integral number of half-waves in said line at said harmonic frequency.
Claim 6
Dependent Claim
60 words
An oscillator according to claim 1 including harmonic load means coupled to said transmission line section on the opposite side of said electron discharge device and spaced from said discharge device axially with respect to said tuning means for receiving and suppressing harmonic frequency energy outside of said cavity portion of said transmission line which resonates to said fundamental frequency.
Claim 7
Dependent Claim
41 words
An oscillator according to claim 5 in which said harmonic load means is a short circuit across said transmission line section spaced axially from said discharge device substantially an integral number of half-wavelengths in said section of said harmonic frequency energy.
Claim 8
Dependent Claim
16 words
An oscillator according to claim 5 in which said harmonic load means includes an energy absorber.
Claim 9
Dependent Claim
25 words
An oscillator according to claim 5 in which said harmonic load means includes a stub-line and means coupling said stub-line to said transmission line section.
Claim 10
Dependent Claim
95 words
An oscillator according to claim 1 including a short circuit across said transmission line located axially in a third region on the side opposite said tuning means relative to said electron discharge device, the effective electrical first distance from said short circuit to said electron discharge device being at least two half-wavelengths in said transmission line of said second harmonic frequency energy, and the effective electrical second distance from said short circuit to said tuning means being an integral number of said half-wavelengths which is at least one of said half-wavelengths less than said first-distance.
Claim 11
Dependent Claim
57 words
An oscillator according to claim 9 including means coupled to said transmission line section on the opposite side of said electron discharge device and spaced from said discharge device axially with respect to said tuning means for suppressing second harmonic frequency energy outside of said cavity portion of said transmission line which resonates to said fundamental frequency.
Claim 12
Dependent Claim
41 words
An oscillator according to claim 1 including voltage-variable reactance frequency-shift means, and means for coupling said frequency shift means to said transmission line in a third region located axially on the side opposite said tuning means relative to said discharge means.
Claim 13
Dependent Claim
37 words
An oscillator according to claim 11 including means coupled to said transmission line section outside said fundamental frequency half-wave cavity portion for suppressing harmonic frequency energy propagating away from said cavity portion in said transmission line section.
Claim 14
Dependent Claim
32 words
An oscillator according to claim 1 in which said transmission line is a section of rectangular waveguide, and said means to extract energy is located in a narrow sidewall of said waveguide.
Claim 15
Dependent Claim
50 words
An oscillator according to claim 13 including a second rectangular waveguide having a cut-off frequency lower than fO oriented with its longitudinal axis perpendicular to said longitudinal axis of said oscillator section and coupled at an end to said oscillator section at said sidewall via said means to extract energy.
Claim 16
Dependent Claim
144 words
An electronic oscillator for providing electromagnetic wave energy at microwave frequencies, comprising a section of transmission line having a longitudinal axis, an electron discharge device which is capable of generating such energy in a range of frequencies including a fundamental frequency fO which is below the cut-off frequency fc of said transmission line, and a harmonic frequency nfO of fO which propagates in a single mode in said transmission line, means coupling said device to a first region in said transmission line section, tuning means in a second region of the transmission line section spaced a known distance along said axis from said first region for tuning a portion of said section including said first and second regions to resonate substantially as a half-wave cavity to said fundamental frequency fO, and means to extract from said transmission line section energy at said harmonic frequency.
Claim 17
Dependent Claim
144 words
An electronic oscillator for providing electromagnetic wave energy at microwave frequencies, comprising a section of transmission line having a longitudinal axis, an electron discharge device which is capable of generating such energy in a range of frequencies including a fundamental frequency fO which is below the cut-off frequency fc of said transmission line, and a harmonic frequency nfO of fO which propagates in a single mode in said transmission line, means coupling said device to a first region in said transmission line section, tuning means in a second region of the transmission line section spaced a known distance along said axis from said first region for tuning a portion of said section including said first and second regions to resonate substantially as a half-wave cavity to said fundamental frequency fO, and means to extract from said transmission line section energy at said harmonic frequency.
Claim 18
Dependent Claim
23 words
An oscillator according to claim 15 including means coupled to said transmission line to enhance the amplitude of energy at said harmonic frequency.
Claim 19
Dependent Claim
39 words
An oscillator according to claim 15 in which said transmission line is a section of rectangular waveguide having a cut-off frequency such that nf0>fc>fO, and said means to extract energy is located at one end of said waveguide section.
Claim 20
Dependent Claim
29 words
An oscillator according to claim 1 including a second transmission line having a cut-off frequency below said fundamental frequency coupled to said portion via said means to extract energy.
References Cited (Backward Citations)
US3715686A
Cited
US3831110A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-11-10 | 1979-05-12 | 1979-11-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-11-10 | 1983-05-12 | 1983-11-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-11-10 | 1987-05-12 | 1987-11-11 | $7700.00 | Window Closed / Lapsed |