Quotables
"We are probably nearing the limit of all we can know about astronomy."
Simon Newcomb, astronomer ; 1888
PatentStorm News
Make the Most of Our Site
See this month's Top Inventors and Most Cited Patents.
Stay on top of the latest innovations by subscribing to an RSS feed.
Registered users: Manage your profile.
| Number | Title | Issue Date |
| 4328554 | Programmable frequency synthesizer (PFS) A programmable frequency synthesizer (PFS) consists of three serially conted stages: an accumulator, a triangle converter, and a sine shaper. The accumulator is the frequency-generating stage of the synthesizer. It consists of an input latch to store the... | 05/04/1982 |
| 4323862 | Frequency shift modulator with circuitry for simple change-over between high and low channels The frequency shift modulator comprises an operational amplifier connected so as to form an integrating circuit and followed by a bistable circuit having trigger hysteresis for producing a two-level voltage which is applied to one end of a first resistor ... | 04/06/1982 |
| 4317209 | FSK Tone generator circuit A tone generator circuit used in a frequency shift keying (FSK) channel in a frequency division multiplexing (FDM) system is disclosed. Each frequency shift between the mark and space tone frequencies is programmed to generate a sequence of discrete inter... | 02/23/1982 |
| 4311971 | Apparatus for generating constant-envelope, angle-modulated pulse signals An improved constant-envelope, angle-modulated pulse signal generator makes use of first and second bi-phase amplitude modulators, each for modulating a carrier with supplied pulse signals. The pulse signals are representative of information and are inter... | 01/19/1982 |
| 4259648 | One-bit frequency-shift-keyed modulator A shift-keyed modulator utilizes a lookup table (41) to provide a binary sequence of digits one at a time. Since the binary digits are selected so that their accumulation represents the amplitudes of a series of points on a theoretical sinusoidal wave, a ... | 03/31/1981 |
| 4238783 | Telemetry system for transmitting analog data over a telephone line An FSK receiver for a single channel analog telemetry system comprises an FSK demodulator, a frequency multiplier, and a frequency-to-voltage converter. An FSK transmitter comprises a voltage-to-frequency converter, a frequency divider, and an FSK tone ge... | 12/09/1980 |
| 4193030 | Frequency hopping communication system A signal modulated with information is hopped to discrete frequencies and its phase is selected to be 0° or 180° in each frequency hop interval under control of a pseudo noise binary code signal produced by a code generator. The discrete frequencies are... | 03/11/1980 |
| 4179588 | Encoder unit for mobile radio transmitter A multi-frequency encoder unit is provided for a mobile radio transmitter which is constructed as a single unitary package comprising a keyboard, a first printed circuit board positioned adjacent to the rear face of the keyboard and which includes a switc... | 12/18/1979 |
| 4134072 | Direct digital frequency synthesizer A desired output frequency can be generated by applying a corresponding digital phase step number to an accumulator to generate multiples of the number for application to a sine wave look-up table from which digital samples of the sine wave amplitude are ... | 01/09/1979 |
| 4091342 | Time delay modulator A time delay modulator is disclosed in which the instantaneous time base of a carrier signal is varied in accordance with a modulating signal. In one embodiment, modulation is achieved through the use of charge transfer delay lines and variable frequency ... | 05/23/1978 |
| 4090135 | Wireless FSK technique for telemetering underground data to the surface A Frequency Shift Keying (FSK) system to transmit and receive data as a sequence of dual frequency short duration tone bursts. Normally the data is transmitted from an underground location, as in a mine, to the surface or to another underground location. ... | 05/16/1978 |
| 4083008 | Method and circuit for generation of digitally frequency-shiftable electric signals A first counter operating as a frequency-shiftable frequency divider is caused to reset before its normal count recycle in one setting of a flip-flop to reduce the factor of frequency division in response to a keying signal. A second counter, operating on... | 04/04/1978 |
| 4079355 | Method for the transmission of binary information by means of a frequency-modulated signal and a circuit for performing that method A transmission of a binary signal which transmission is immune to interference is obtained by transmitting the bits of the binary signal by means of a frequency-modulated signal in which a cycles of a first frequency f1 are followed by b cycles... | 03/14/1978 |
| 4039952 | Digital frequency shift-keyed transmitter The square-wave output of a comparator is coupled back to the input of an RC controlled integrator including an operational amplifier and an inverter circuit with an output signal maintained at a predetermined level. The RC network sets the pulse repetiti... | 08/02/1977 |
| 4032891 | Signal transmitter using an active thick film substrate A battery powered portable acoustic transmitter comprises a plurality of single-pole, momentary contact switches, a type 555 pulse producing integrated circuit chip, and an electroacoustic transducer and matching tuning coil. An RC timing circuit includes... | 06/28/1977 |
| 4003001 | Multi-line, multi-mode modulator using bandwidth reduction for digital FSK and DPSK modulation A frequency shift keyed (FSK) modulator capable of substantially simultaneously modulating a plurality of binary encoded data signals at different baud rates and modulation frequencies for substantially simultaneous transmission over a plurality of commun... | 01/11/1977 |
| 3997855 | Digital FSK time rate of change modulator A digital FSK time rate change modulator is responsive to a digital input signal and generates either a first or a second output frequency. The FSK modulator switches from one output frequency to the other in small increments over a predetermined time int... | 12/14/1976 |
| 3987374 | Multi-line, multi-mode modulator using bandwidth reduction for digital FSK and DPSK modulation A multi-line multi-mode modulator uses compatible digital modulation techniques for multifrequency (MF), frequency shift keyed (FSK) and differential phase shift keyed (DPSK) modulation to achieve a multi-line multi-mode modulator which is capable of hand... | 10/19/1976 |
| 3958191 | Multi-line, multi-mode modulator using bandwidth reduction for digital FSK and DPSK modulation A multi-line multi-mode modulator uses compatible digital modulation techniques for multifrequency (MF), frequency shift keyed (FSK) and differential phase shift keyed (DPSK) modulation to achieve a multi-line multi-mode modulator which is capable of hand... | 05/18/1976 |
