429 results about "Digital clock" patented technology

An RF signal source receives wideband digital signals representing the instantaneous amplitude of the desired RF, and ΣΔ converts to ternary ΣΔ signals. The ternary ΣΔ signals are delayed in a transversal filter and the delayed signals are converted to currents for application to a traveling-wave summer for producing the desired RF. The traveling-wave summer may be a transmission line. The currents may be weighted with a filter response in order to limit the bandwidth of the RF signals. The RF may be coupled out through an antialiasing filter. The digital clocks may be delayed to correspond with the delays of the combiner, to impart directionality to the summed signals.

A global time reckoning system simultaneously indicates local time and global time. The global time reckoning system can be practiced with standard clock timer drivers, including electromechanical and digital clock motors, in combination with a novel global time system clock face to allow a user to reckon time locally or anywhere on the globe without time zone conversion calculations. The global time system clock face has multiple time scales, at least one of which is driven by the clock drive in cooperation with an hour indicator (e.g., an hour hand). The global time system clock face simultaneously displays global time (relative to any location on the globe) and local time. Additionally, the global time reckoning system, with the appropriate clock timer driver is adaptable to indicate a number of other global time related information, including sunrise/sunset, days of the week, lunar phase and solstices/equinoxes.

The invention discloses a high-precision time interval measurement method based on phase modulation. Under the control of digital clock phase-shift, a path of high-frequency and low-jitter clock is transformed to N paths of clock signals having same frequency and fixed phase difference, and is taken as a counter reference clock; a counter is driven to count respectively in N paths of clock periods; two paths of clock signals, which have the smallest error, are extracted by utilizing the clock phase information; through the combination with the clock period and the counted values, the measurement valve of the time interval is worked out. Compared with the method using a single clock for counting, the high-precision time interval measurement method effectively reduces the measurement principle error, and can improve the measurement resolution ratio to 1/n of the reference clock. A measurement device is connected with a signal conditioning module, an FPGA module, a singlechip module and a display circuit module sequentially according to the signal processing order, and realizes high measurement precision, high measurement resolution ratio, high measurement speed, real time display, and stable and reliable work under a certain crystal oscillation frequency; and the integration in the FPGA is easy, and the expansion is flexible. The high-precision time interval measurement method can be used for measuring the speed in a high-speed motion.

Devices for enabling a user to locate an object, animal or person or reminding the user of the location of an object, animal or person. In a non-transmitter/receiver embodiment, the device includes at least one alert mechanism which is connected to a digital clock or other timer and microprocessor which times transmission of alert signals emitted from the alert mechanism or mechanisms. The operational components of the device may be contained in a housing which is attached to the object, animal or person to be located. In a remote transmitter/receiver embodiment, the device includes a transmitter which transmits activation signals at preset times to activate an alert feature of a paired remote receiver which is provided on the object, animal or person to be located or tracked. The transmitter may include an on-command button for manual transmission of the activation signals to the receiver. The receiver may have a visible alert mode in combination with a selected audible or vibratory alert mode. In an on-board transmitter/receiver embodiment, the device includes a transmitter which is housed together with a receiver in a single unit. In that case, the transmitter of one unit can transmit preset timed activation signals to the receiver of a different unit which is placed on the object, animal or person. Alternatively, the transmitter of one unit can transmit preset timed activation signals to the receiver of the same unit placed on the object, animal or person.

A flash drive incorporating a FM scanner radio, of which the circuitry is electrically isolated from each other and separately powered to reduce production cost and size. The flash drive-radio combination comprises a radio and a flash drive encased in a housing. The radio is configured only to search, receive, and convert to audio signals, radio signals that lies within only the broadcast FM bands, and the flash drive comprises a flash memory, a bidirectional communication port, a controller, and preferably, a display unit for displaying used and available memory in the flash memory. A write protect switch, a channel scan button, a digital clock may be further included in the present invention.

The invention discloses a clock recovery device and a clock recovery method. The clock recovery device comprises an analog-to-digital converter, a digital signal processing circuit, a digital-to-analog converter and a voltage-controlled oscillator which are connected in turn, wherein the voltage-controlled oscillator is connected with the analog-to-digital converter; the analog-to-digital converter is used for converting received analog signals into digital signals, and sending the digital signals to the digital signal processing circuit; the digital signal processing circuit is used for carrying out phase demodulation and filtering processing on the received digital signals so as to obtain digital clock error signals, and sending the digital clock error signals to the digital-to-analog converter; the digital-to-analog converter is used for converting the received digital clock error signals into control voltage signals, and sending the control voltage signals to the voltage-controlled oscillator; and the voltage-controlled oscillator is used for generating a synchronous clock according to the received control voltage signals, and outputting the synchronous clock to the analog-to-digital converter. The invention can provide a reference clock for chips in a digital circuit.

An article is described for providing illumination for a door handle in reduced lighting conditions. The article includes a mounting device and a method for illuminating the door handle. The method for illuminating may comprise a timekeeping device such as a light emitting display digital clock.

A mixed signal system includes a digital circuit (17) clocked by a digital clock signal, an analog circuit (18) clocked by an analog clock signal, and clock generation circuitry (15) including a delay locked loop (20) including a N-cell delay line (21) having an input for receiving a reference clock signal and a plurality of delay outputs (22), and a multiplexer (30) having a plurality of inputs coupled to the plurality of delay outputs (22), respectively. A selection signal (34) causes the multiplexer (30) to couple a selected one of the delay outputs (22) to an output (32) of the multiplexer (30) so as to cause the analog clock signal and the digital clock signal to be sufficiently skewed from each other to minimize an inaccuracy in the analog circuit (18) caused by a noise glitch associated with the digital clock signal.

A unique high performance digital video recorder having a number of novel features. The recorder's electronics are all on a unitary printed circuit board. The recorder also requires at least one hard disk drive and audio and video input analog signals (from a source such as video camera or broadcast media) as well as a suitable monitor for receiving output audio and video analog signals. A external time code generator (i.e., VITC digital clock) is also required for synchronization. Also required are various manual control devices (i.e., panel controls) for mode selection. The electronics of the preferred embodiment comprise A-to-D and D-to-A converters, a hard disk interface, a JPEG compression encoder/decoder, a multi-port DRAM and DMA subsystem, a microprocessor with RS-232 and RS-422 access ports, various working memory devices and bus interfaces and a 16-bit stereo digital audio subsystem. Novel features of the preferred embodiment include use of an index table for disk addresses of recorded frames, a multi-port memory controller in the form of a field programmable gate array (FPGA), loop recording using dual channels, and dynamic JPEG compression compensation.

A transceiver having an RF receiver, in particular VHF receiver, with digital signal processing in a digital part. The transceiver having an input part, at least one mixer and an intermediate frequency/baseband processing device, having a local channel oscillator, to which a first phase locked loop with a phase discriminator and an adjustable first frequency converter are assigned, and having a reference oscillator for the phase locked loop and the control clock of the digital signal processing device, in which, in order to acquire the control clock, a digital clock synthesizer is provided to which an output signal of the reference oscillator is supplied, and a control signal is supplied by the digital part in the form of a digital tuning word, the frequency of the reference oscillator being selected such that its order of magnitude is at least equal to the bandwidth of one or more of the reception bands used, and none of its harmonics occur in a reception channel.

An automatic test system using a DDS signal generator to create a signal with high spectral purity or a low jitter digital clock. The low jitter clock has variable frequency and is programmed to control other test functions, such as the generation of arbitrary waveforms. The DDS uses a high resolution, high sampling rate DAC to generate a sine wave that is converted to a digital clock. The architecture of the DDS signal generator allows low cost CMOS circuitry to be used to generate the data stream that feeds the high sample rate DAC.

A phase-locked loop (PLL) has an analog divider in the feedback path that receives either the in-phase or quadrature-phase pair of outputs from a voltage-controlled oscillator (VCO) while the other pair, 90-degree out-of-phase, of outputs from the VCO is used for the PLL output. Phases between the PLL's input and output are inherently aligned. The analog output of the analog divider is converted to a digital clock signal and applied to a cascade of digital dividers to generate a reduced feedback clock. The reduced feedback clock is applied to the D input and the digital clock signal is applied to the clock input of a pseudo D-flip-flop that drives the feedback input of a phase-frequency detector that drives the charge pump to the VCO input. Another cascade of digital dividers and pseudo D-flip-flop re-align the reference clock input to the phase-frequency detector. Analog and digital re-alignment circuits reduce internal skew.

A system and method are provided for controlling the duty cycle and frequency of a digitally generated clock. The method accepts a first clock signal having a fixed first frequency. A frequency control word with a first pattern is loaded into a first plurality of serially-connected registers. A duty cycle control word with a second pattern is loaded into a second plurality of serially-connected registers. A register clock signal is generated in response to the first clock and the first pattern. Then, a digital clock signal is generated having a frequency and duty cycle responsive to the register clock signal and the second pattern.

The invention discloses a signal processing system and a signal processing method. A sampling and preprocessing device samples and preprocesses input signals according to oscillation signals output by an oscillation device, and sends obtained sampling values to an adaptive equalization filter to perform equalization; the signals after the equalization are divided into two paths, wherein one path is a signal output, while the other path is sent to a phase demodulator; the phase demodulator detects the phase error of each sampling value to obtain a phase error signal which is sent to a loop filter to filter noises and high-frequency components of the phase error signal so as to obtain a digital clock error signal; the digital clock error signal is sent to the oscillation device which generates the oscillation signals according to the digital clock error signal; and the oscillation signals are sent to the sampling and preprocessing device. In the system and the method, the adaptive equalization filter is embedded in a clock synchronization loop to perform the equalization during clock synchronization, so the influence, caused by signal distortion, on phase demodulation is weakened, the clock synchronization and equalization are performed effectively, the signal crosstalk of a communication transmission system is eliminated, and the signal processing capacity of a receiving end is improved.

A digital clock generator includes a base clock generator for generating a base clock signal at a variable base clock frequency in response to a control signal. A digital clock controller generates a digital clock signal having a substantially constant number of digital clock cycles over a predetermined period.

A system for recovering and aligning synchronous data transmissions is disclosed. The system includes a transmitter configured to transmit a source clock signal and a number of data groups over a number of channels with different latencies/propagation delays. The data groups are transmitted during the same clock cycle pursuant to the source clock signal. Each data group is transmitted over a corresponding media channel. The system also includes a receiver configured to receive the source clock signal and the data groups over the corresponding channels and to re-align or recover the wide word that comes in on the channels that are skewed. The receiver further includes: for each channel, (a) a local clock configured to generate a local clock signal based on the source clock signal, the local clock signal being phase-shifted from the source clock signal by a predetermined amount of phase shift, (b) a logic device configured to clock in the data group received over the channel using the local clock signal, (c) a sequence number generator configured to generate a sequence number associated with the data group, (d) a FIFO configured to store and output the clocked-in data group and the associated sequence number, (e) a memory device configured to store the clocked-in data group from the FIFO using the associated sequence number as a memory address, the memory device further configured to output a predetermined portion of its contents after a predetermined capacity threshold is reached. The transmitter is further configured to transmit a start-of-cell signal to the receiver. The sequence number generators are synchronized upon receiving an alignment cell, which is identified by a start-of-cell signal having a specific value for a predetermined cycle period. In one implementation, the receiver is implemented using a number of field programmable gate arrays and the local clocks are implemented using digital clock managers associated with the field programmable gate arrays.

This invention is fiber-optical transmission method for drawing far away the TD-SCDMA system base station radio-frequency digit. The radio-frequency signal receiver-transmitter in wireless base station and base band digital signal processing part in wireless base station are separated and drawn far away to antenna neighborhood. After digitizing the intermediate-frequency port of radio-frequency signal receiver-transmitter, the received and transmitted digital data stream signal, controlling or detecting digital signal and referenced clock signal are respectively modulated to corresponding light wavelength. After making the optical signals corresponded to each radio-frequency receiver-transmitter confluent, an optical fiber is used to up-transmitting and down-transmitting respectively. At the receiving end, the confluent signal is split in terms of wavelength. The split signals are demodulated to corresponding digital signals respectively. This invention also provides the radio-frequency signal receiver-transmitter and indoor base station interface card matching this transmission method.