Patent US3624550A successfully refreshed from Google Patents.
US3624550A
Expired / Lapsed
US
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Microwave oscillator circuit for a bulk-effect negative-resistance device
Assignee: Varian Medical Systems Inc
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Filing: 1969-06-16
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Granted: 1971-11-30
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Expires: 1989-06-16
Abstract
Abstract A microwave oscillator circuit for a high-power high-efficiency negative-resistance bulk-effect device is disclosed. The circuit includes a half-wavelength open-circuited length of stripline transmission line provided with variable lumped capacitors at opposite ends thereof, such capacitors serving to tune the stripline for a fundamental mode of resonance at the operating frequency of the oscillator. The low-impedance bulk-effect device is connected across the stripline at a point near the voltage null of the fundamental resonance. The characteristic impedance and the length of the stripline are adjusted such that the reactance of the line and the reactance of the capacitors at the ends allow the circuit to support full wave resonance at precisely twice the fundamental frequency and therefore develop a second harmonic voltage across the bulk-effect device to improve the conversion efficiency of the oscillator. Power is extracted from the oscillator circuit by means of a filter circuit tuned to pass the fundamental frequency and reject the harmonic. The invention herein described was made in the course of or under a contract or subcontract thereunder with the Department of the Air Force.
Inventors
- 👤 Arthur B Vane
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 14:26
CPC Classifications
H; H03; H03B; H03B9/00; H03B9/12; H03B9/14; H03B9/147
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
211 words
In a microwave oscillator circuit, means forming a length of stripline transmission line, a pair of variable lumped capacitors connected in shunt with said stripline at opposite ends thereof to define a half-wavelength resonator open-circuited at its ends and tuned for a fundamental mode of resonance at the operating frequency of the oscillator, a bulk-effect negative-resistance semiconductive device connected in shunt with said resonated stripline at a point intermediate the length thereof such point of connection being near the voltage null of said resonator for the fundamental mode of resonance for matching the low impedance of the bulk-effect device to the low impedance of said resonator near said voltage null, THE IMPROVEMENT WHEREIN, the product of capacitance and self inductance of said capacitors at the second harmonic of the operating frequency of the oscillator is substantially greater at one end of said stripline than the other end to position the voltage null of the second harmonic of the oscillator near the position of said bulk-effect device to improve the conversion efficiency of the oscillator, and further including the provision of a capacitive member connected in shunt with said stripline substantially at the position of said bulkeffect device to facilitate the start of oscillation of the oscillator at the fundamental operating frequency.
Claim 2
Dependent Claim
211 words
In a microwave oscillator circuit, means forming a length of stripline transmission line, a pair of variable lumped capacitors connected in shunt with said stripline at opposite ends thereof to define a half-wavelength resonator open-circuited at its ends and tuned for a fundamental mode of resonance at the operating frequency of the oscillator, a bulk-effect negative-resistance semiconductive device connected in shunt with said resonated stripline at a point intermediate the length thereof such point of connection being near the voltage null of said resonator for the fundamental mode of resonance for matching the low impedance of the bulk-effect device to the low impedance of said resonator near said voltage null, THE IMPROVEMENT WHEREIN, the product of capacitance and self inductance of said capacitors at the second harmonic of the operating frequency of the oscillator is substantially greater at one end of said stripline than the other end to position the voltage null of the second harmonic of the oscillator near the position of said bulk-effect device to improve the conversion efficiency of the oscillator, and further including the provision of a capacitive member connected in shunt with said stripline substantially at the position of said bulkeffect device to facilitate the start of oscillation of the oscillator at the fundamental operating frequency.
Claim 3
Dependent Claim
34 words
The apparatus of claim 1 including a slab of thermally conductive insulative material disposed inbetween the stripline conductors of said resonator in heat exchanging relation therewith to facilitate heat sinking of said bulk-effect device.
Claim 4
Dependent Claim
28 words
The apparatus of claim 1 wherein said stripline is dimensioned to have a characteristic impedance less than 10 ohms to provide a low surge impedance of said stripline.
Claim 5
Dependent Claim
123 words
The apparatus of claim 1 including a second length of stripline, a second pair of lumped capacitors connected in shunt with said second stripline at opposite ends thereof to define a half-wavelength resonator open circuited at its ends and tuned for a fundamental mode of resonance at the operating frequency of the oscillator, said second resonant stripline being electromagnetically coupled to said first stripline resonator, said second capacitors having values of capacitance and inductance to detune the second harmonic of said second stripline resonator from the second harmonic frequency of the oscillator, an output coupling means coupled to said second stripline resonator for extracting the output microwave energy from said second resonant stripline, whereby the second harmonic output of the oscillator is suppressed.
Claim 6
Dependent Claim
37 words
The apparatus of claim 1 wherein said bulk-effect device is a Gunn effect diode dimensioned to have a transit time mode frequency of operation within + or - 30 percent of the operating frequency of the oscillator.
References Cited (Backward Citations)
US3416099A
Cited
US3512105A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-11-29 | 1975-05-31 | 1975-11-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-11-29 | 1979-05-31 | 1979-11-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-11-29 | 1983-05-31 | 1983-11-30 | $7700.00 | Window Closed / Lapsed |