US3857099A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Mixer for controlling the frequency accuracy of a variable frequency oscillator
Assignee: United States Department of the Army
•
Filing: 1973-05-08
•
Granted: 1974-12-24
•
Expires: 1993-05-08
Abstract
Abstract A mixer for a frequency synthesizer system that controls the frequency accuracy of a variable frequency oscillator of a radio transmitter and which includes a balanced amplifier that is nonconductive except when switched on by each of identical periodic impulses shaped to include a predetermined number of successive harmonics from the fundamental on, all having approximately equal amplitude, and a selected frequency input from the variable frequency oscillator to the balanced amplifier so that the mixer output includes a predetermined narrow frequency band that is less than said fundamental.
Inventors
- 👤 D Lohrmann
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 16:34
CPC Classifications
H; H03; H03B; H03B21/00; H03B21/01
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
103 words
A mixer comprising: means for delivering a single frequency from within a predetermined band, conversion means operable on received sinusoidal energy for delivering periodic pulses that contain a fundamental frequency and a predetermined number of successive harmonics, that have maximum amplitude deviation on the order of 3db within a combined bandwidth slightly greater than one-half said predetermined band harmonics outside the bandwidth being attenuated, means for mixing single frequency energy delivered by said first recited means and said periodic pulses and providing an output frequency band of bandwidth numerically less than said fundamental frequency and centered at the center of said predetermined band.
Claim 2
Dependent Claim
103 words
A mixer comprising: means for delivering a single frequency from within a predetermined band, conversion means operable on received sinusoidal energy for delivering periodic pulses that contain a fundamental frequency and a predetermined number of successive harmonics, that have maximum amplitude deviation on the order of 3db within a combined bandwidth slightly greater than one-half said predetermined band harmonics outside the bandwidth being attenuated, means for mixing single frequency energy delivered by said first recited means and said periodic pulses and providing an output frequency band of bandwidth numerically less than said fundamental frequency and centered at the center of said predetermined band.
Claim 3
Dependent Claim
120 words
A mixer as defined in claim 1 wherein said means for mixing includes a Class A balanced transistor amplifier, output means coupled to the collectors of the transistors of said amplifier, said means for delivering a single frequency being coupled to the bases of the transistors of said amplifier, and wherein said conversion means for delivering periodic pulses includes a normally nonconducting transistor switch means with its collector and emitter in series with the emitters of the transistors of said amplifier, said transistor switch means being normally nonconductive, said means for delivering the periodic pulses further including means operable to convert an input sine wave at the fundamental frequency to said periodic pulses that turn on said transistor switch means.
Claim 4
Dependent Claim
70 words
A mixer as defined in claim 1 wherein said conversion means for delivering the periodic pulses includes means operable in response to a sine wave input at said fundamental frequency to provide an approximately rectangular wave of the same period and with one steep side, and a third order pulse shaping network coupled to said means that provides the approximately rectangular wave to provide, in response thereto, said periodic pulses.
Claim 5
Dependent Claim
48 words
A mixer as defined in claim 3 wherein said third order pulse shaping network includes an inductor and two capacitors, in series, connected across the output of the means providing the rectangular wave, and resistance means connected across that one of the two capacitors remote from said inductor.
Claim 6
Dependent Claim
85 words
A mixer as defined in claim 2 wherein said means for delivering the periodic pulses includes means operable to convert a sine wave input at the frequency of said fundamental to an approximately rectangular wave operable to convert the rectangular wave to said periodic pulses, said third order pulse shaping network including an inductor and two capacitors, in series, connected across the output of said means providing the rectangular wave, and resistance means connected across that one of the two capacitors remote from said inductor.
Claim 7
Dependent Claim
65 words
A mixer as defined in claim 5 wherein said means operable to convert a sine wave input to an approximately rectangular wave includes a PNP transistor, a load resistor in series with the collector for developing the approximately rectangular wave, and a diode having its anode connected to the base of said PNP transistor and its cathode connected to the emitter of said PNP transistor.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-12-23 | 1978-06-24 | 1978-12-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-12-23 | 1982-06-24 | 1982-12-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-12-23 | 1986-06-24 | 1986-12-24 | $7700.00 | Window Closed / Lapsed |