788 results about "Narrow bandwidth" patented technology

A novel apparatus and method of improving the power efficiency of a digital transmitter for non-constant-amplitude modulation schemes. The power efficiency improvement mechanism of the invention leverages the high efficiency of a switched-mode power supply (SMPS) that supplies the high DC current to the transmitter's power amplifier, while compensating for its limitations using predistortion. The predistortion may be achieved using any suitable technique such as digital signal processing, hardware techniques, etc. A switched mode power supply (i.e. switching regulator) is used to provide a slow form (i.e. reduced bandwidth) of envelope tracking (based on a narrower bandwidth distorted version of the envelope waveform) such that the switching regulator can use a lower switching rate corresponding to the lower bandwidth, thereby obtaining high efficiency in the switching regulator. The resulting AM-AM and AM-PM distortions in the power amplifier are compensated through predistortion of the digital amplitude modulating signal which dictates the envelope at the PA input. Similarly, the phase modulation is also compensated prior to the PA, such that once it undergoes the distortion in the PA, the end result is sufficiently close to the desired phase.

Organic vertical-cavity surface-emitting lasers ("OVCSELs"), in which a thin layer of organic material is disposed between highly reflective mirrors to thereby form a vertical cavity within a stacked arrangement. The lasers of the present invention each comprise a first mirror layer; a layer of active organic material over the first mirror layer; and a second mirror layer over the layer of first active organic material. The active organic material lases when pumped to thereby produce laser light. The present invention provides for optical semiconductor lasers with desired properties such as narrow bandwidth emission, the minimal use of active organic materials, and the facilitation of wavelength tuning and electrical pumping.

A circular-polarization dipole helical antenna is used for electronic device and satellite terminal and includes a base, and an antenna conductor arranged on surface of the base. The antenna conductor includes a plurality of metal conductors with high Q value and anti-oxidation property and continuously and helically coated on surface of the base. The base is made of low loss and high dielectric constant material. An unbalance-to-balance circuit module connects two signal-feeding ends to the base with phase difference of 180 degree. The problems of narrow bandwidth, low efficiency, complicated structure and precise manufacture can be solved.

An extensible binary mark-up language is disclosed that is compatible with existing XML standards yet provides significantly improved efficiencies for XML-based data storage and communications, particularly for narrow and low bandwidth communication media. A corresponding extensible non-binary mark-up language is also disclosed that is compatible with the XML standard. This dual-representation common message format (CMF) allows standard XML tools to be utilized in viewing and editing XML-based data and allows a CMF parser to be utilized to convert the XML formatted information into an extensible binary representation for actual communication through a medium or storage on a wide range of media. Advantages include a very compact, yet flexible and extensible binary data representation (CMF-B) for a corresponding extensible mark-up language (CMF-X), a data packaging scheme that allows for the effective transport of XML-based data over existing data channels, including narrow-bandwidth channels that utilize existing network protocols, and a CMF parser that allows for seamless conversion between CMF-B and CMF-X.

Systems and / or methods for supporting communications at a reduced bandwidth with a full bandwidth network such as a long-term evolution (LTE) network may be disclosed. For example, inband assignments such as downlink assignments and / or uplink grants may be provided and / or received and transmissions may be monitored and / or decoded based on the inband assignment. Additionally, information (e.g. a definition or configuration) associated with an ePDCCH may be provided and / or received and ePDCCH resources may be monitored and / or decoded based on such information. An indication for support of a reduced bandwidth by the full bandwidth network may also be provided and / or received and control channels in the reduced or narrow bandwidth may be monitored and / or decoded based on the indication. A PRACH preamble and / or a multi-type sub frame definition may also be provided and / or used for support of such a reduced bandwidth.

A first irradiation portion that radiates white light onto a subject, a second irradiation portion that radiates narrow bandwidth light having a narrower wavelength bandwidth than the white light, and an observation window used to observe the subject are respectively disposed on a leading end surface of an endoscope insertion portion. Each of the first and second irradiation portions includes a pair of irradiation windows for emitting light therefrom. A straight line passing through a center point of the observation window and bisecting the leading end surface is defined as a boundary line. The pair of irradiation windows of the first irradiation portion are disposed on both sides of the boundary line. The pair of irradiation windows of the second irradiation portion are disposed on the both sides of the boundary line. Spectra of lights radiated from the irradiation windows of the second irradiation portion can be changed individually.

A wireless communication device is implemented to include a communication interface and a processor. The processor is configured to process communications associated with the other wireless communication devices within the wireless communication system to determine one or more traffic characteristics of those communications as well as one or more class characteristics of the other wireless communication devices. The processor is configured to classify the communications into one or more access categories based on the one or more traffic characteristics and is configured to classify the other devices into one or more device class categories based on the one or more class characteristics. The processor is then configured to generate one or more channel access control signals based on these classifications. The communication interface of the device is configured to transmit the one or more channel access control signals to one or more of the other devices.

A method and system for a Radio Frequency (RF)-based identification, tracking and locating of objects. The method and system use a narrow bandwidth signal in VHF of lower frequency range, which minimizes propagation loss and loss of accuracy of the RF locating signals. The signal is sent from a Master Unit(s) to a Tag. The signal traveling time is recorded and the distance between the Master(s) and the Tag is calculated. The method and system allow achieving a longer distance of the RF signal penetration and an increased accuracy by using VHF bands. The techniques of Digital Signal Processing and Software-Defined Radio are used. The actual waveforms transmitted and received by the radios are defined by the software. The roles of the Master Unit(s) and the Tag can be reversed.

A digital predistortion amplifier design compensates for non-linear amplification of an input signal using predistortion techniques. The design provides a reduced noise floor by using separate digital to analog converters (DAC) to separately convert the input signal and an error correction signal. Furthermore, the input signal can be separated into two or more subbands of narrower bandwidth. Each of the subbands are converted to analog using a separate DAC. By reducing the power and / or bandwidth to be handled by any one DAC, the available levels of quantization of the DAC are applied to a lower power signal and therefore the signal to noise ratio resulting from the conversion process is improved. In addition, each digital subband is passed through a correction filter, which is driven by an adaptive control processing and compensation estimator to compensate for relative gain, phase, and delay inconsistencies between the different subbands.

A method and system for a Radio Frequency (RF)-based identification, tracking and locating of objects. The method and system use a narrow bandwidth signal in VHF of lower frequency range, which minimizes propagation loss and loss of accuracy of the RF locating signals. The signal is sent from a Master Unit(s) to a Tag. The signal traveling time is recorded and the distance between the Master(s) and the Tag is calculated. The method and system allow achieving a longer distance of the RF signal penetration and an increased accuracy by using VHF bands. The techniques of Digital Signal Processing and Software-Defined Radio are used. The actual waveforms transmitted and received by the radios are defined by the software. The roles of the Master Unit(s) and the Tag can be reversed.

A method and system for a long range Radio Frequency (RF)-based identification, tracking and locating of objects. The method and system use a narrow bandwidth ranging signal(s), including VHF of lower frequency bands, which minimizes propagation loss and loss of accuracy of the RF locating signals. The method and system includes narrow bandwidth ranging signal multi-path mitigations processor, which further improves the track-locate accuracy. The signal is sent from a Master Unit(s) to a Tag. The signal traveling time is recorded and the distance between the Master(s) and the Tag is calculated. The method and system allow achieving a longer distance of the RF narrow bandwidth ranging signal penetration and an increased accuracy by using VHF bands in conjunction with the narrow bandwidth ranging signal multi-path mitigations processor. The techniques of Digital Signal Processing and Software-Defined Radio are used. The actual waveforms transmitted and received by the radios are defined by the software. The roles of the Master Unit(s) and the Tag can be reversed.

A digital predistortion amplifier design compensates for non-linear amplification of an input signal using predistortion techniques. The design provides a reduced noise floor by using separate digital to analog converters (DAC) to separately convert the input signal and an error correction signal. Furthermore, the input signal can be separated into two or more subbands of narrower bandwidth. Each of the subbands are converted to analog using a separate DAC. By reducing the power and / or bandwidth to be handled by any one DAC, the available levels of quantization of the DAC are applied to a lower power signal and therefore the signal to noise ratio resulting from the conversion process is improved. In addition, each digital subband is passed through a correction filter, which is driven by an adaptive control processing and compensation estimator to compensate for relative gain, phase, and delay inconsistencies between the different subbands.

A novel apparatus and method of reduced power consumption for battery backup operation of a communication device such as a cable modem. When the cable modem senses a failure of the external power source it requests from the cable head-end to switch from multi-channel DOCSIS 3.0 operation to single-channel DOCSIS 2.0 operation. In response to approval by the cable head-end, the cable modem shuts down multi-channel circuits in the PHY such as the wideband analog to digital converter (ADC) which is normally used during multi-channel operation. In its place, it activates narrowband circuitry such as a narrowband ADC which consumes far less power. Tuner filter circuits are also swapped to match the reduced bandwidth requirements of battery backup operation. To further reduce power, the narrower bandwidth requirements during battery backup operation permit the linearity of a programmable gain amplifier (PGA) in the upstream path to be reduced.

Wideband signal generation systems and methods are provided which employ frequency interleaving for generating wideband signals. A general method increases a digitally synthesized signal's bandwidth by frequency interleaving multiple digitally synthesized signal sources of narrower bandwidth. Frequency interleaving creates a continuous wideband signal by summing multiple narrower band signals that overlap in frequency. According to certain embodiments, digital signal processing (DSP) and analog mixing are used to create the multiple narrower band signals such that a high fidelity, continuous wideband signal is produced when the multiple narrower band signals are summed.

A lidar system capable of remotely identifying calibrated absolute aerosol backscatter coefficients of atmospheric aerosol particles by transmitting a beam of light and spectrally separating the intensity of Rayleigh and Mie backscattering is disclosed. The transmitter features high pulse energy to generate sufficient Rayleigh backscattering, enabling atmospheric scanning in a timely manner. The transmitter employs a seeded Nd:YAG laser and a seeded stimulated Raman scattering wavelength shifter to achieve narrow bandwidth, eye-safe laser pulses. The receiver employs a telescope, collimating lens, beam splitter, molecular absorption filter, focusing lenses, and avalanche photodiodes. Mie backscattering is blocked by the molecular absorption filter to provide a Rayleigh signal, which is used with knowledge of atmospheric density to calibrate the Mie signal. The system is intended for atmospheric research and aerosol monitoring applications where calibrated Mie scattering intensity is necessary to measure the optical depths of aerosol structures such as plumes, clouds, and layers.

A semiconductor nanocrystal compound is described which is capable of linking to one or more affinity molecules. The compound comprises (1) one or more semiconductor nanocrystals capable of, in response to exposure to a first energy, providing a second energy, and (2) one or more linking agents, having a first portion linked to the one or more semiconductor nanocrystals and a second portion capable of linking to one or more affinity molecules. One or more of these semiconductor nanocrystal compounds are linked to one or more affinity molecules to form a semiconductor nanocrystal probe capable of bonding with one or more detectable substances in a material being analyzed, and capable of, in response to exposure to a first energy, providing a second energy. In one embodiment, the probe is capable of emitting electromagnetic radiation in a narrow wavelength band and / or absorbing, scattering, or diffracting energy when excited by an electromagnetic radiation source (of narrow or broad bandwidth) or a particle beam. The probe is stable to repeated exposure to energy in the presence of oxygen and / or other radicals. Treatment of a material with the semiconductor nanocrystal probe, and subsequent exposure of this treated material to a first energy, to determine the presence of the detectable substance within the material bonded to the probe, will excite the semiconductor nanocrystal in the probe bonded to the detectable substance, causing the probe to provide a second energy signifying the presence, in the material, of the detectable substance bonded to the semiconductor nanocrystal probe. In one embodiment, the semiconductor nanocrystals in the probe are excitable over a broad bandwidth of energy, and emit electromagnetic radiation over a narrow bandwidth, making it possible to use a single energy source to simultaneously excite a plurality of such probes, each emitting electromagnetic radiation of a differing wavelength band to simultaneously analyze for a plurality of detectable substances in a material being analyzed. Also described are processes for respectively making the semiconductor nanocrystal compound and the semiconductor nanocrystal probe. Processes are also described for treating materials with the probe, for example, to determine the presence of a detectable substance in the material bonded to the probe.

The present patent application comprises a transmitting method and apparatus 240. A signal source 241 provides an input signal to a low-pass filter 242 which filters the input signal to produce a filtered signal. The filter 242 is selectively operable in a first mode in which the input signal is filtered within a narrower bandwidth; and in a second mode in which the input signal is filtered within a broader bandwidth. The filtered signal is output to a modulator 243 which modulates the filtered signal to produce a modulated signal. The modulated signal is output to a transmitter 244 which transmits the modulated signal.

A technique for noise reduction in a wireless communication system uses controllable bandwidth filters (120) to filter a received signal. In a typical implementation, the filters (120) are used at baseband frequencies. A measurement (RSSI) is indicative of the strength of the received signal. A control circuit (144) generates a control signal (146) to control the bandwidth of the filters (120). If the received signal strength is above a first threshold, a wider bandwidth may be used for the filters (120). If the received signal is below a second threshold, the control circuit (144) generates the control signal (146) to set the filters (120) to a more narrow bandwidth. The system (100) may also be used with digital filters (150, 152) following digitization by analog to digital converters (ADCs) (130, 132). The system (100) is particularly well-suited for operation with noise-shaped ADCs (130, 132), such as Delta-Sigma converters.

A high frequency signal receiver comprising a variable gain amplifier, a first filter for restricting a bandwidth of an analog baseband signal, an AD converter connected to the first filter, a second filter for restricting the bandwidth of an output of the AD converter, an interference wave detection circuit for detecting the level of an interference wave in the received signal, and a controller for controlling the first filter to have a wide bandwidth when the level of the interference wave is lower than a threshold level, and switching the first filter to have a narrow bandwidth while changing the characteristics of the second filter so as to compensate deterioration of the pass-band of the first filter when the level of the interference wave is equal to or greater than the threshold level.

An encoder comprising an input for inputting frames of an audio signal in a frequency band, at least a first excitation block for performing a first excitation for a speech like audio signal, and a second excitation block for performing a second excitation for a non-speech like audio signal. The encoder further comprises a filter for dividing the frequency band into a plurality of sub bands each having a narrower bandwidth than the frequency band. The encoder also comprises an excitation selection block for selecting one excitation block among the at least first excitation block and the second excitation block for performing the excitation for a frame of the audio signal on the basis of the properties of the audio signal at least at one of the sub bands. The invention also relates to a device, a system, a method and a storage medium for a computer program.

Objects of the present invention are to reduce the number of optical filters, and to improve crosstalk characteristics of periodic optical filters. WDM signals are converted into vestigial-side-band signals collectively using a periodic optical filter. As an example, light signals having odd number wavelengths (wavelengths lambda1, lambda3, lambda5) and light signals having even number wavelengths (wavelengths lambda2, lambda4, lambda6) are wavelength-multiplexed in the first optical wavelength multiplexer, and are then filtered by a periodic narrow band-pass optical filter to convert the light signals into vestigial-side-band (VSB) signals. Then, the vestigial-side-band signals are combined by the second optical wavelength multiplexer. Such an interleave configuration enables suppression of crosstalk caused by adjacent channels.

The invention provides a decoding method of an audio signal. The encoding method includes the following steps: when the audio signal corresponding to the received coding stream switched from the relatively wide bandwidth to the relatively narrow bandwidth, low band signal component of the audio signal is obtained and high band information is extended; the time-varying fade-out treatment is carried out to extended high band information to obtain processed high band information component; the processed high band information component and the low band signal component are combined. By the method provided by the embodiment of the invention, when the audio signal switches from the wide band to narrow band, a series of treatments, such as bandwidth detection, manual band spreading, time-varying fade-out treatment and bandwidth combination are available to realize smoothing switch from a wide band signal to a narrow band signal, thus achieving a more comfortable auditory feeling of human ears.

The present invention discloses a simple, low cost method to fabricate light emitting source using luminescent colloid nanoparticles. It uses monodispersed colloid light emitting nanoparticles of oxides, semiconductors, and polymers to fabricate high quality, narrow bandwidth light emitting source. The colloid particles can be dispersed homogeneously in liquid that can be coated easily on a substrate using a simple coating method such as spray, dip coating or spin coating. There is no restriction on the size or shape of the substrate. Therefore, a low cost, large area, high efficiency and reproducible light emitting source can be made easily.

An illumination system comprising a laser light source and a wavelength conversion module for generating high brightness illumination by photoluminescence. The wavelength conversion module comprises an optical element comprising a wavelength conversion medium, set in a mounting for thermal dissipation, and an optical concentrator. The shape of the optical element and its reflective surfaces provides improved light extraction at the converted wavelength, and allows for more effective cooling. It provides a compact light source with a configuration suitable for applications that require high brightness and narrow bandwidth illumination at a selected wavelength, e.g. for fluorescence microscopy, or other applications requiring étendue-limited optical fiber coupling. The system, which preferably uses a solid state laser diode, provides an alternative to conventional arc lamps, and addresses limitations of other available solid state LED light sources to provide high brightness at some wavelengths, particularly in the 580nm to 630nm range.

A dimming controller for an LED lamp controls dimming using an adaptive filter to reduce or eliminate perceivable flickering and to provide smooth transitions during active dimming. During stable conditions, the adaptive filter operates with a relatively narrow bandwidth to filter noise that may lead to perceivable flickering. During active or startup conditions, the adaptive mapping filter operates with a high bandwidth to provide a quick response to the dimmer switch.

An ultrasound test apparatus for polymeric materials (e.g., plastic pipes) includes a low-absorption housing that at least partially encloses an ultrasound transducer, wherein the transducer emits a low frequency wide angle ultrasound beam with a narrow bandwidth. In especially preferred configurations and methods, the apparatus will detect flaws in polymeric pipes, and especially in welds or stressed zones of such pipes, wherein defects of less than 4% of the wall thickness (up to 4 inches) are detected. Further disclosed are configurations and methods for nondestructive detection of lack-of-fusion defects in polymeric pipes.

An antenna system includes an antenna element and an electromagnetic bandgap element proximate the antenna element wherein the electromagnetic bandgap element is optimized for narrow bandwidth operation thereby providing radiofrequency selectivity to the antenna system. Preferably the electromagnetic bandgap element is tunable such as through use of a bias-alterable dielectric substrate or other tuning mechanism. The design approach also provides a means of creating an ultra-thin low-profile narrowband tunable channel selective antenna system suitable for low frequency applications.

A method and apparatus is disclosed for measurement and monitoring of in-band optical signal to noise ratio (OSNR). A two channel optical spectrum analyzer (OSA) is advantageously applied in acquiring wavelength division multiplex (WDM) signal data after it has been split according to polarization, then deriving the in-band OSNR from acquired data due to its narrow bandwidth, selective spectral shape, and capability to analyze two components of a polarized signal simultaneously. The in-band OSNR can be measured without interrupting optical transmission traffic in the network.

A grating pulse compressor configuration is introduced for increasing the optical dispersion for a given footprint and to make practical the application for chirped pulse amplification (CPA) to quasi-narrow bandwidth materials, such as Nd:YAG. The grating configurations often use cascaded pairs of gratings to increase angular dispersion an order of magnitude or more. Increased angular dispersion allows for decreased grating separation and a smaller compressor footprint.