613 results about "Frequency generation" patented technology

A digital and analog television signal digitization and processing device that performs the digitization and processing functions using a common reference frequency source that is used to generate multiple subclock signals, wherein the reference frequency source is independent of any synchronizing characteristic of the input signal. For dual channel analog signal processing, the common frequency source is not locked to either channel/input signal. Digital signal processing is accomplished based on the same common reference frequency source. Advantageously, the present invention allows all of the analog-to-digital converters and decoder circuitry/logic necessary for simultaneously digitizing and processing several analog and digital television signals to be integrated on a single integrated circuit as well as eliminating duplicate frequency generation circuits.

A method for biological tissue ablation includes shaping a shapeable RF antenna to accommodate the contour of a body vessel adjacent a biological tissue load; generating a train of radio frequency (RF) energy pulses at an output frequency for transmission in a transmission line to the shapeable RF antenna adjacent the biological tissue load; sensing a reflected signal and a forward signal of the RF energy pulses; and adjusting output frequency of the RF energy pulses to effect a substantial match of transmission line impedance with shapeable RF antenna and biological tissue load impedance.

A fiber-laser-based implementation of a Terahertz source through difference frequency generation (DFG) by nonlinear optical (NLO) crystals is compact, tunable and scalable. A pair of fiber lasers (Q-switched, CW or mode-locked) generate single-frequency outputs at frequencies ω1 and ω2. A fiber beam combiner combines the laser outputs and routes the combined output to a THz generator head where a nonlinear interaction process in the NLO crystal generates THz radiation.

One embodiment of the present invention includes a frequency generation circuit including a control module, an oscillator circuit coupled to the control module, the oscillator circuit having a start-up time defined by the time required to reach a desired frequency. The oscillator circuit includes an amplifier having an input and an output and being programmably-alterable by the control module, a first capacitor coupled to the input of the amplifier and being programmably-alterable, in capacitance, by the control module, a second capacitor coupled to the output of the amplifier, a crystal resonator coupled to the first and second capacitors for generating an output signal having a desired frequency, wherein fast start-up time is achieved.

An apparatus and method for calibrating a non-crystal oscillator in a transceiver unit using a crystal-oscillator includes the step of establishing a time base based upon oscillations of the crystal oscillator. A comparison of the number of oscillations for the non-crystal oscillator and the crystal oscillator is made during a known time period is made. An adjustment is determined based upon the established time base and the compared number of oscillations. The transceiving of the transceiver unit is then controlled based upon this adjustment.

A high index contrast waveguide based source for radiation. In some embodiments, the radiation is in the 0.5-14 Terahertz regime. Waveguides are provided that permit the generation of radiation at the sum and/or difference frequency of two input beams. In order to control the power level within the waveguide, embodiments in which pluralities of similar or identical waveguide are provided, and the input radiation is divided among the plurality of waveguides. The output radiation can be steered by applying phased array methods and principles.

An LED driving circuit package includes a rectification unit to receive an AC power voltage and rectify the AC power voltage to generate a ripple voltage, an LED driving switching unit including a plurality of switch units and a plurality of current control units. The LED driving circuit package further includes a low voltage control unit including a circuit power supply unit to generate low voltage power, a voltage detection unit to detect a magnitude of the ripple voltage, a reference frequency generation unit to generate a reference frequency, and a reference pulse generation unit to generate a reference pulse for controlling the operation of the LED driving switch unit according to the reference frequency and a magnitude of the voltage detected by the voltage detection unit.

Methods and systems are provided for frequency generation suitable for use in wireless devices capable of operating at multiple frequencies. Such systems may change the loop gain of an automatic frequency control loop based on the operating frequency of the wireless device. Furthermore, such a frequency dependent loop gain may be carried out by the selection of subroutines with differing loop gains associated with the subroutines. Furthermore, the loop gain may also be temperature compensated based on the temperature of the wireless device and/or the operating frequency of the device.

An embodiment of the present invention relates to a method and apparatus for correcting errors in stereo images. The apparatus for correcting errors in stereo images according to an embodiment of the present invention comprises: a space histogram generation unit generating space histogram information using the depth map information on the input image data; a peak frequency generation unit generating a peak frequency using the 2D image data of the input image data; an object analysis unit determining the error in each frame of the input image data on the basis of the space histogram and peak frequency; a depth map error correction unit correcting the depth map information to reduce the error; and a rendering processing unit generating left and right eye images, which are stereo images, by using the corrected depth map information.

A direct digital frequency synthesizer having a multi-modulus divider, a numerically controlled oscillator and a programmable delay generator. The multi-modulus divider receives an input clock having an input pulse frequency f_osc and outputs some integer fraction of those pulses at an instantaneous frequency f_Vp that is some integer fraction (1/P) of the input frequency. The multi-modulus divider selects between at least two ratios of P (1/P or 1/P+1) in response to a signal from the numerically controlled oscillator. The numerically controlled oscillator receives a value which is the accumulator increment (i.e. the number of divided pulse edges) required before an overflow occurs that causes the multi-modulus divider to change divider ratios in response to receiving an overflow signal. The numerically controlled oscillator also outputs both the overflow signal and a delay signal to the delay generator. The delay signal contains phase-dithering noise that is induced by input into the accumulator of an increment generated from a pseudo-random noise generator. The delay signal further controls the frequency of the multi-modulus divider output signal (V_p) to provide an output signal (V_D) with an f_OUT that has improved phase and timing jitter performance over prior art direct digital frequency synthesizer architectures.

A method and a system are implemented in the fabrication of a portable high power terahertz beam source that can produce a tunable, high power terahertz beam over the frequency from 0.1 THz to 2.5 THz. The terahertz source employs a recycling pump beam method and a beam quality control device. The beam quality control device may or may not be required for a high power terahertz beam generation. In exemplary embodiments, a lithium niobate (LiNbO₃) crystal or a lithium niobate crystal doped with 5% magnesium oxide (LiNbO₃:MgO) can be used. Other nonlinear optical crystals, including GaSe can be used in place of the LiNbO₃ crystal. Through proper alignment of a pump beam, along with recycling a pump beam, high conversion efficiency is achieved, and a high output power beam is produced at terahertz frequencies.

A direct digital frequency synthesizer having a multi-modulus divider, a numerically controlled oscillator and a programmable delay generator. The multi-modulus divider receives an input clock having an input pulse frequency f_osc and outputs some integer fraction of those pulses at an instantaneous frequency f_Vp that is some integer fraction (1/P) of the input frequency. The multi-modulus divider selects between at least two ratios of P(1/P or 1/P+1) in response to a signal from the numerically controlled oscillator. The numerically controlled oscillator receives a value which is the accumulator increment (i.e. the number of divided pulse edges) required before an overflow occurs that causes the multi-modulus divider to change divider ratios in response to receiving an overflow signal. The numerically controlled oscillator also outputs both the overflow signal and a delay signal to the delay generator that further controls the frequency of the multi-modulus divider output signal (V_p) to provide an output signal (V_D) with an f_OUT that has improved phase and timing jitter performance over prior art direct digital frequency synthesizer architectures.

A superbroadband or multiwavelength laser transmitter source for wavelength-division multiplexing, two-wavelength interferometry, differential lidar and optical storage applications. Contrary to conventional tunable laser sources that can switch between different lasing wavelengths in a given wavelength band, the superbroadband laser simultaneously emits at multiple wavelengths. The basic idea of this system is to maintain simultaneous lasing operation in an optical active gain medium at different wavelengths. The system uses a novel dispersive cavity. By designing this cavity structure appropriately, the system creates its own microcavities each lasing at a different wavelength within the fluorescence band of the gain medium. Mode competition in the proposed cavity is absent and spectral range of simultaneous multi-frequency generation is considerably enhanced practically to the spectral width of the active media luminescence spectrum. As a result, the radiation of each mode with its own wavelength is amplified in the active media independently from the simultaneous amplification of the rest of the wavelengths.

A temperature compensation method for quartz crystal oscillator, the temperature sensor and compensation frequency generation circuit producing a compensation frequency signal having equal absolute value and opposite sign with the deviation frequency value produced by uncompensated quartz crystal oscillator, said compensation frequency signal mixed and outputted with the uncompensated frequency signal after wave shaping, obtaining compensated frequency signal after filtering by filter, said invention has low phase noise and can make effective temperature compensation to high frequency overtone quartz crystal oscillator.

A wideband frequency generator has two or more oscillators for different frequency bands, disposed on the same die within a flip chip package. Coupling between inductors of the two oscillators is reduced by placing one inductor on the die and the other inductor on the package, separating the inductors by a solder bump diameter. The loosely coupled inductors allow manipulation of the LC tank circuit of one of the oscillators to increase the bandwidth of the other oscillator, and vice versa. Preventing undesirable mode of oscillation in one of the oscillators may be achieved by loading the LC tank circuit of the other oscillator with a large capacitance, such as the entire capacitance of the coarse tuning bank of the other oscillator. Preventing the undesirable mode may also be achieved by decreasing the quality factor of the other oscillator's LC tank and thereby increasing the losses in the tank circuit.