Did You Know...
...that in the early 1940s GE engineer James Wright was charged with a task of utmost importance to the war effort: develop a cheap substitute for rubber that could be used to produce tires, gas masks and a whole host of military gear. Wright tackled the task diligently -- and wound up inventing Silly Putty.
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| Number | Title | Issue Date |
| 5625324 | Ultra low noise frequency generator producing the sum of plural signal sources The frequencies of N oscillators are summed to provide a signal generator output signal. Because the phase noise power spectral densities of the oscillators add as power, the frequency summed output exhibits a noise degradation over a single oscillator of... | 04/29/1997 |
| 5592507 | Intermediate relay station of a digital microwave communication system using service channel for monitoring and controlling space and/or time diversity, heterodyne relay, phase control, frequency control, with phase shift keying modulation A microwave digital communication system PSK-modulates a microwave carrier by using a main signal and, further, frequency-modulates it by using a service channel (SC) signal for monitoring and controlling the system. An intermediate relay station employin... | 01/07/1997 |
| 5577073 | Frequency and phase-locked two-phase digital synthesizer For use with a quartz angular rate sensor, a frequency and phase-locked synthesizer recovers a reference signal virtually free of phase noise, and generates a quadrature-phase reference signal for complex demodulation of the angular rate signal. The synth... | 11/19/1996 |
| 5559419 | Method and apparatus for transducerless flux estimation in drives for induction machines Power is provided to the stator windings of an AC induction machine which includes a component at the fundamental drive frequency for the machine and a superimposed signal component which is at a substantially higher frequency than the drive power. The fu... | 09/24/1996 |
| 5559475 | Frequency synthesizer for synthesizing signals of a variety of frequencies by cross modulation A frequency synthesizer in which a PLL synthesizer 50 generates signals of frequency steps of an integer times a target frequency step. A base band generator 2 digitally generates sine wave signal components of the target frequency step. The outputs from ... | 09/24/1996 |
| 5408201 | Frequency synthesizer using three subfrequency synthesizers for generating two different frequencies A frequency synthesizer includes three subfrequency synthesizers: a first synthesizer generating a first subfrequency varying in units of a frequency step, a second synthesizer generating a second subfrequency varying in units of a frequency step being N ... | 04/18/1995 |
| 4912432 | Plural feedback loop digital frequency synthesizer A multiple feedback loop frequency synthesizer, having a first and a second feedback loop, each fed by one of a pair of reference frequency signals having a frequency separation equal to the desired frequency separation of the output signals provided by t... | 03/27/1990 |
| 4673891 | Frequency synthesizer having first phase locked loop frequency multiplied by near unity in second phase locked loop A Frequency synthesis stage comprises two phase locked loops. The first (O1, D1, M, CP1, D2) divides the frequency Fo+Ɗ derived from preceding stages by N/Q, N being a variable integer, and adds to the result a... | 06/16/1987 |
| 4631499 | Phase-locked loop for a directly mixing synchronous AM-receiver A phase-locked loop is constituted by a controllable oscillator coupled through a phase detection arrangement and a low-pass filter to receive an input carrier applied to a signal input of the phase detection arrangement. In order to decrease the phase sy... | 12/23/1986 |
| 4603304 | Reference frequency generation for split-comb frequency synthesizer A frequency synthesizing apparatus of the closed-loop design employing a first frequency mixing means to provide a continuous constant increment frequency coverage over a given output signal frequency range. The first frequency mixing means is responsive ... | 07/29/1986 |
| 4580289 | Fully integratable superheterodyne radio receiver utilizing tunable filters A radio receiver from antenna to detector designed to be realized substantially on an integrated-circuit chip comprises a single tunable oscillator and a plurality of mixers. An input signal from an antenna is connected as an input to a first mixer and mi... | 04/01/1986 |
| 4517530 | Maser cavity servo-tuning system Two collocated, weakly coupled probes, on loop and one dipole, detect the magnetic and electric fields inside a maser cavity. Signals from the probes are compared in phase, and the signal output from the phase detector is applied to a varactor, the reacta... | 05/14/1985 |
| 4453137 | Signal processor for plural frequency detection and tracking over predetermined range of frequencies A signal processor circuit including a plurality of similar cascaded stages, each of which is capable of locking onto and tracking a different frequency of a multiple-frequency composite signal applied to the processor. Each of the stages may comprise a f... | 06/05/1984 |
| 4368437 | Wide frequency range signal generator including plural phase locked loops A wide band oscillator with phase lock loop is controlled by signals from an 40 MHz harmonics generator combined with the output of another phase lock loop controlled oscillator whose selectible outputs vary in MHz steps with a total range of 39 MHz. The ... | 01/11/1983 |
| 4347483 | Frequency and phase lock loop with separated AFC and phase locking A frequency and phase lock loop is disclosed in which AFC and phase locking functions are completely separated thus permitting signal acquisition range and closed loop bandwidth parameters to be independently established. Interference between phase lock l... | 08/31/1982 |
| 4340974 | Local oscillator frequency drift compensation circuit The invention provides a double superheterodyne receiver having the usual first and second frequency changers associated with first and second local oscillators. The second local oscillator is provided as a voltage controlled oscillator and means are prov... | 07/20/1982 |
| 4339826 | Radio receiver having phase locked loop frequency synthesizer A radio receiver comprises a frequency conversion circuit connected between a frequency-variable local oscillator and a divide-by-N programmable counter incorporated in a phase locked loop frequency synthesizer and adapted to continuously change the frequ... | 07/13/1982 |
| 4303893 | Frequency synthesizer incorporating digital frequency translator The use of a digital frequency translator, using pulse snatching techniques, for multiplying the output frequency of a precise and accurate frequency synthesizer by a preselected certain numerical fraction permits the frequency synthesizer to be referred ... | 12/01/1981 |
| 4272730 | Microwave frequency synthesizer utilizing a combination of a phase locked loop and frequency translation techniques A microwave frequency synthesizer utilizing a phase locked loop for generating a wide range of microwave frequencies in response to a control signal, in combination with a network including a plurality of distinct frequency local oscillators that are appr... | 06/09/1981 |
| 4246546 | Apparatus and method for locking a PLL onto a selected offset frequency sideband The output of a VCO, a referenced frequency signal and an offset frequency signal are mixed to provide a control signal for the VCO and a double offset frequency signal which is mixed with an output of the offset frequency source to provide a DC component... | 01/20/1981 |
| 4137508 | Channel selection system for a displaced spectrum frequency synthesizer A comparator-discriminator is provided, suitable for use with a phaselock control system of a frequency synthesizer, to permit automatic tuning of a variable oscillator to a selected frequency lying within a frequency band for which a phaselock may occur.... | 01/30/1979 |
| 4097816 | Tuning system A system is disclosed for generating a plurality of preselected frequencies in a radio frequency device such as a receiver, transmitter or transceiver. It comprises means for generating a first reference signal having a predetermined frequency and means, ... | 06/27/1978 |
| 4095190 | Tuning system A system is disclosed for generating a plurality of preselected frequencies in a radio frequency device such as a receiver, transmitter or transceiver. It comprises two crystal-controlled reference signal oscillators. First and second controllable variabl... | 06/13/1978 |
| 4072909 | Automatic phase and frequency control system An automatic phase and frequency control system includes a pair of multipliers coupled to a source of input signal. A voltage controlled oscillator is also coupled to each of the multipliers. Means are provided to phase shift the oscillator signal at one ... | 02/07/1978 |
| 3946329 | Electronic automatic frequency tuning system Apparatus and method for providing an automatic frequency tuning system capable of supplying a local oscillator signal with a preselected frequency. The frequency of an output signal of the local oscillator is electronically varied across a frequency regi... | 03/23/1976 |
