58 results about "Sweep generator" patented technology

A distance to PIM measurement circuit is made using a device such as an AWS transceiver that has separate transmit and receive bands. With a typical AWS transceiver placed in close proximity to a PCS transceiver, the AWS device will include a band reject filter to eliminate interference from the PCS signals. The PIM measurement circuit includes two frequency sources F1 and F2 that are provided through a combiner for characterization of the PIM circuit. To enable distance determination, an FM measurement is created by using a offset sweep generator attached to one of the two frequency sources. To avoid frequencies blocked by the band reject filter, a desired harmonic of a test PIM harmonic signal is selected outside the band of the band reject filter. In one embodiment, a reference signal is provided by mixing a signal from an ×M multiplier connected to the F1 source with an ×N multiplier signal connected to the F2 source, the mixed output being filtered to select the desired harmonic reference signal to avoid the band reject filter. In another embodiment, a reference signal is created by generating all harmonics of the combined F1 and F2 signal using a series connected amplifier and clipping diodes with a filter again used to select the desired harmonic reference signal to avoid the band reject filter.

A lamp inverter with continuous strike voltage facilitates faster striking of a fluorescent lamp, especially at cold temperatures. A frequency sweep generator sweeps the frequency of the lamp inverter to a striking frequency corresponding to a striking lamp voltage and then maintains the striking frequency until the lamp strikes.

A PIM measurement circuit enables making forward and reverse PIM measurements on any 1 port (reflection) or 2 port (transmission) device with the ability to determine in distance where individual PIM impairments are located as well as their magnitude. The PIM measurement circuit includes two frequency sources that are provided through a combiner for a CW characterization of the PIM circuit. To enable distance determination, an FM measurement is created by using a saw tooth offset sweep generator attached to one of the two frequency sources. With downconversion and processing of signals from the PIM impairments, the FM signal provides a frequency variation that is converted using a Fourier transform or spectrum analysis for separation of frequencies, enabling determination of the distance of the PIM sources as well as their magnitudes.

A method and apparatus for measuring acoustic energy applied to the head to detect increases in intracranial pressure. Acoustic eye patches are applied to a patient's eye or eyelid, and an ultrasonic sweep generator applies an acoustic signal across the patient's skull, the signal being swept across a predetermined range. The eye patches have piezoelectric film sensors for measuring the acoustic signal. In one embodiment the predetermined range is in the ultrasonic band and an analyzer determines from the output of the sensors a resonant frequency and a damping of acoustic amplitude at said resonant frequency, there being a correlation between said damping and intra cranial pressure. In another embodiment the predetermined range includes a range less than 20 kHz and the analyzer determines retinal artery pulsations, with pressure being applied to the eye until the pulsations disappear, such pressure being a measure of intra cranial pressure.

An apparatus for, and methods of use for, measuring film thickness on an underlying body are provided. The apparatus may include at least one Impedance Resonance (IR) sensor, which may include at least one sensing head. The at least one sensing head may include an inductor having at least one excitation coil and at least one sensing coil. The excitation coil may propagate energy to the sensing coil so that the sensing coil may generate a probing electromagnetic field. The apparatus may also include at least one power supply, at least one RF sweep generator electrically connected to the excitation coil; at least one data acquisition block electrically connected to the sensing coil; at least one calculation block; and at least one communication block. Methods of monitoring conductive, semiconductive or non-conductive film thickness, and various tools for Chemical Mechanical Polishing / Planarization (CMP), etching, deposition and stand-alone metrology are also provided.

A distance to PIM measurement circuit is made using a device such as an AWS transceiver that has separate transmit and receive bands. With a typical AWS transceiver placed in close proximity to a PCS transceiver, the AWS device will include a band reject filter to eliminate interference from the PCS signals. The PIM measurement circuit includes two frequency sources F1 and F2 that are provided through a combiner for characterization of the PIM circuit. To enable distance determination, an FM measurement is created by using a offset sweep generator attached to one of the two frequency sources. To avoid frequencies blocked by the band reject filter, a desired harmonic of a test PIM harmonic signal is selected outside the band of the band reject filter. In one embodiment, a reference signal is provided by mixing a signal from an xM multiplier connected to the F1 source with an xN multiplier signal connected to the F2 source, the mixed output being filtered to select the desired harmonic reference signal to avoid the band reject filter. In another embodiment, a reference signal is created by generating all harmonics of the combined F1 and F2 signal using a series connected amplifier and clipping diodes with a filter again used to select the desired harmonic reference signal to avoid the band reject filter.

The invention belongs to the technical field of mobile communication technology, in particular to a sweep frequency and propagation model coverage prediction-based frequency optimization method, which is characterized by comprising the following steps of: testing main roads through a sweep generator to acquire sweep frequency data; establishing an interference model based on the sweep frequency and the coverage prediction and fusing a sweep frequency data rasterized road damage matrix and a coverage prediction road damage matrix; establishing a dynamic evaluation function based on the interference model; and searching a frequency optimization scheme according to the dynamic evaluation function and continuously repeating the searching to obtain an optimized frequency optimization scheme. In the sweep frequency and propagation model coverage prediction-based frequency optimization method, the sweep frequency which is measured data consistent with user perception is fully utilized; meanwhile, the propagation model coverage prediction is integrated; and the interference model is established by fusing the sweep frequency and the propagation model coverage prediction, and the dynamic evaluation function is established based on the accurate model so as to effectively search the frequency optimization scheme which meets the requirement.

A frequency modulated continuous wave (FMCW) radar is described. The radar includes a first discriminator for receiving a portion of the swept frequency signal generated by a frequency sweep generator and for producing a reference difference-frequency signal of frequency equal to the difference between the frequency of the swept frequency signal and the frequency of a time displaced swept frequency signal derived from the swept frequency signal. An analogue-to-digital converter is provided for sampling the target difference-frequency signal at a rate derived from the frequency of the reference difference-frequency signal. A processor (88) for determining frequency components of the digitized target difference-frequency signal is arranged to determine for at least one frequency component of the digitized target difference-frequency signal any phase difference between frequency sweeps of said swept frequency signal. The radar may be used for detecting foreign object debris (FOD) on runway surfaces and the like. A corresponding method of operating an FMCW radar is also described.

The invention discloses a local-point fault detection method for a marine low-voltage power cable based on an FDR method. A sweep generator (1) emits a segment of sinusoidal sweeping-frequency signals to the detected cable (3), fault information of the initial end (8) of the detected cable is returned to a wave detector (2), a total-reflection voltage waveform is displayed via a display device (7) a waveform frequency difference deltaf is obtained from the total-reflection voltage waveform, a distance L between a fault point and an incident point is calculated according to a formula L=150Vp / deltaf, and Vp as a known quantity represents the speed ratio of the cable. According to the invention, possible faults as open circuit and short circuit of the marine low-voltage power cable can be located accurately, and the method is characterized by high positioning precision, simple operation, less loss, low cost, high safety and the like.

A high frequency sweep generator uses a DDS-PLL method for frequency sweep over wide frequency spans. A digital sweep generator produces a linear ramp signal using DDS techniques that is applied to a coarse tuning port of a high frequency tunable oscillator, such as a YIG tunable oscillator (YTO). A PLL has as inputs an accurate linear swept frequency sinusoid from a DDS and a linear swept frequency output signal from the YTO to produce an error correction signal that is applied to a fine tuning port of the high frequency tunable oscillator. The error correction signal compensates for any non-linearities introduced into the linear swept frequency output signal by the high frequency tunable oscillator.

The invention discloses a method for measuring an azimuth angle of a mobile communication base station antenna, and includes the steps of: performing a drive test on a cellular mobile communication network, and measuring radiation relative gain distribution information of a target base station antenna at each azimuth angle of an installation horizontal plane; based on the shape characteristics of a gain envelope line formed by the radiation relative gain distribution information, extracting main lobe distribution of the target base station antenna in a horizontal direction and a central ray angle; and obtaining the azimuth angle of the antenna according to the main lobe distribution information and the central ray angle. According to the method for measuring the azimuth angle of the mobile communication base station antenna, people do not need to purchase or install special hardware by climbing up to a tower, and can complete measurement only by utilizing drive test data of an existing drive test terminal and sweep generator, the cost is low, and engineering implementation is easy; and a calculation result is high in degree of accuracy and stability, and a requirement for optimizing work of the cellular mobile communication network can be satisfied.

The invention discloses a method for conjoint analysis of a mobile network condition by using a sweep generator and a testing mobile phone. The method comprises the following steps of: (1) importing sweep generator drive test data and testing mobile phone drive test data; (2) preprocessing the sweep generator drive test data and the testing mobile phone drive test data respectively; (3) analyzing a mobile network scene; (4) performing conjoint analysis on the sweep generator drive test data and the testing mobile phone drive test data and outputting a summary report of neighbor cells of disparate systems in a whole network; and (5) outputting an analysis result and a suggestion on optimization. According to the method, a scene analysis result and a neighbor cell configuration suggestion are obtained by processing and analyzing the imported sweep generator drive test data and testing mobile phone drive test data, the two items of data are subjected to conjoint analysis, meanwhile, an analysis result is displayed in a GIS (Geographic Information System), a network problem and a problem hidden trouble are positioned, the purposeful suggestion on optimization is given, and help is offered for optimization of a mobile network.

A radar apparatus measures at least one characteristic of at least one object. A sweep generator generates a sweep signal to modulate an oscillator to generate a varying frequency signal. A transmitter transmits the varying frequency signal as a radar signal. A receiver receives a reflected radar signal to produce a received signal using the varying frequency signal. A compensation signal memory holds a previously stored compensation signal. A compensation circuit compensates the received signal based on the previously stored compensation signal to produce a compensated received signal. A quiet switch quiets the reflected radar signal and determines the previously stored compensation signal, during calibration of the radar apparatus, and the received signal is written into the compensation signal memory. Switched loads can be used to quiet the reflected radar signal. For field calibration, the compensated signal can be adjusted but not necessarily written back into the compensation signal memory.

The invention discloses a poisonous and harmful gas concentration on-line testing method. The method comprises 1, starting a broadband light source, and respectively transmitting the broadband light beam into a measurement gas chamber and a reference gas chamber, 2, detecting light transmission intensity of the reference gas chamber by an optical detector and transmitting a signal into a divider, 3, shooting broadband light into the measurement gas chamber, detecting light intensity by the optical detector, carrying out treatment by a light detector and a digital lock-in-amplifier and transmitting the signal into the divider, 4, scanning oscillator frequency by a sweep generator, and setting doubled modulation frequency as a reference signal by a frequency doubler, 5, separating alternating current and direct current parts of a gas concentration electrical signal by a circuit of the optical detector, and feeding the alternating current part into the digital lock-in-amplifier, and 6, carrying out treatment by a gas concentration computing model to obtain a concentration value of gas to be detected and outputting and displaying the concentration value of the gas. The poisonous and harmful gas concentration on-line testing method can effectively improve a measurement precision of poisonous and harmful gas and has measurement safety and reliability.

A temporally and frequency controlled amplified cardiac stethoscope device is provided wherein frequency response selection is carried out by manually tuning two active filters thereby permitting user pass band (high and low frequency cutoff) selection. Simultaneously, the user is able to select a time window, or interval, of the audio output of the device for specific aural observation, to the exclusion of the remainder of cardiac cycle sounds. The device is miniaturized to permit transport in a clothing pocket and use in the clinic or at the bedside. The device is based upon electrocardiographic QRS complex / electronic Schmitt trigger synchronization of a sweep generator and comparator. The synchronization signal, in combination with manual user inputs, permits the control of digital / analog switching of on / off time intervals of a variable frequency response electronic stethoscope.

A lamp inverter with continuous strike voltage facilitates faster striking of a fluorescent lamp, especially at cold temperatures. A frequency sweep generator sweeps the frequency of the lamp inverter to a striking frequency corresponding to a striking lamp voltage and then maintains the striking frequency until the lamp strikes.

The present invention discloses a method and apparatus for producing a narrow line laser emission that can be tuned at frequency rates exceeding 100 kHz. The laser apparatus is capable of fast scanning speeds close to multiples of the cavity resonance frequency. The laser cavity can be either a ring or a line resonator. This comprises dispersive means and a nonlinear medium, whose parameter when modulated induces mode-locking, referred from now on as a mode-locking mechanism block, an optical amplifier used as a gain medium and a splitter that ensures that a certain percentage of the laser emission from the gain medium is tapped outside the cavity. The driving method is accomplished with an electronic mechanism that includes a controller drive sweeping generator and a voltage controlled oscillator that injects a tunable radio frequency signal into the nonlinear mode-locking mechanism block. In particular, a semiconductor amplifier can accomplish both functions of amplification and mode-locking, by driving it with RF signals. Two resonant mechanisms are employed to modulate in frequency the mode-locking mechanism block (usually the optical gain in a semiconductor amplifier) and to achieve high frequency tuning rates. The configuration is compatible with working at sweeping rates close to multiples of the cavity resonance frequency as well as with buffering for increased tuning speeds.

The invention discloses a transformer winding deformation live testing system. The system includes two signal injection mechanisms, each signal injection mechanism includes a sweep signal generator, the sweep signal generators are connected to protection circuits, the protection circuits are connected to the output ends of the signal injection mechanisms through coupling capacitors, and current transformers are arranged between the protection circuits and the coupling capacitors; the two signal injection mechanisms are connected to a neutral point busing and a high-voltage bushing end screen of a transformer winding respectively; the two current transformers are connected to an industrial control computer through RC filters, signal amplifiers and data acquisition channels. The invention also discloses a testing method of the abovementioned transformer winding deformation live testing system. The transformer winding deformation live testing system and testing method thereof can improve the defects of the prior art, reduce interference brought by operation of a transformer itself, and improve test precision.

The invention belongs to the field of instrument measurement and particularly relates to a sweep generator based on digital zero intermediate frequency. In the sweep generator, a sweep frequency source has three paths of outputs; the first path is connected with one end of a to-be-tested network; the second path is respectively connected with two analog multipliers; the third path is only connected with the second analog multiplier; the other end of the to-be-tested network is connected with the first analog multiplier; output ports of the two analog multipliers are respectively connected with input ports of two analog filters; output ports of the two analog filters are respectively connected with input ports of two paths of digital analog converters; output ports of the two paths of digital analog converters are connected with different ports of a digital signal processing module; the digital signal processing module is used for realizing the digital zero intermediate frequency orthogonalization, phase difference and amplitude ratio calculation for the output signals of the two paths of digital analog converters and outputting the result. According to the sweep generator, the design difficulty of the simulating sweep frequency source is reduced, the influence caused by the quantization error of the digital device is reduced, the software calculation difficulty is reduced and the measurement precision is improved.

The invention discloses a device and method for detecting the EVA cross linking degree through sound waves. The device comprises a swept signal generator, an energy converting processor, a sweep generator and a computer. The energy converting processor is composed of a receiving type energy converter and a sending type energy converter. The output end of the swept signal generator is connected with the input end of the sending type energy converter, the output end of the receiving type energy converter is connected with the signal input end of the sweep generator, the signal output end of the sweep generator is connected with the computer, the swept signal generator is connected to the computer through the sweep generator, the sending type energy converter converts electric signals generated by the swept signal generator into the sound waves, the sent sound waves are received by the receiving type energy converter and converted into electric signals, and the electric signals of the swept signal generator and the electric signals of the receiving type energy converter are scanned by the sweep generator, converted into waveforms and sent to the computer. The device is simple in structure, short in detection time, economical, environmentally friendly and capable of rapidly judging the EVA cross linking condition through the transmission decay characteristics of the sound waves in EVA materials.

The present invention relates to an arrangement for phase locking of a Voltage Controlled Oscillator (VCO) to a selected frequency harmonic among a number of predetermined or available frequencies (harmonics), comprising a reference generator for generating a reference frequency, a phase lock loop (1; 101; 10, 4, 5, 6, 9) for producing an output signal in response to the input reference frequency, said phase lock loop comprising (enclosing) a phase detector (1), a loop filter (10), said VCO (5), adding means (4) and a power splitter (6). The arrangement also includes a sweep generator (9). It further comprises or is associated with storing means 82) for storing information about, for each selectable or available frequency harmonic, a first (coarse) control voltage providing a VCO frequency output which is lower / higher than, and differs from the selected frequency (harmonic) by a given value (Δf1). That the sweep generator (9) adds (superimposes) a controllable sweep voltage to / on the first control voltage at least until a varying, second frequency difference (Δfc) between the output VCO frequency and the selected frequency harmonic reaches a given value. Monitoring / detecting means are provided for detecting the varying, second frequency difference (Δfc) between the selected frequency harmonic and the VCO output frequency, and sweep generator control means are provided for reducing the sweep rate until the VCO is phase locked to the selected frequency harmonic.

An electron microscope capable of producing EELS (electron energy-loss spectroscopy) has a spectral position correcting signal supply circuit for supplying a spectral position correcting signal H to a first driver amplifier to project spectra at the center of a CCD camera This correcting signal H corresponds to a beam deflection signal A′ supplied from a scan generator to a second driver amplifier, an excitation signal B′ supplied from an intermediate lens excitation signal supply circuit to a third driver amplifier, and another excitation signal supplied from a projector lens excitation signal supply circuit to a fourth driver amplifier.

The invention discloses a method and device for detecting the quality of a communication system based on a sweep generator, and the method comprises the following steps: using the sweep generator to acquire frequency points of a disturbed cell and cell parameter identifier (CPI) information which are provided by testing software; synchronizing to the disturbed cell according to the information of the frequency points of the disturbed cell and the CPI information; detecting a downlink synchronization code corresponding to the synchronized disturbed cell, and determining an uplink pilot time slot (UpPTS) window according to the downlink synchronization code; sweeping the downlink synchronization code corresponding to a disturbing cell scanned by the UpPTS window, and synchronizing to the disturbing cell according to the downlink synchronization code; and detecting cell identification information corresponding to the synchronized disturbing cell, and determining the disturbing cell according to the cell identification information. According to the technical scheme, UE (user equipment) with the use of a downlink traffic channel can be detected on the basis of the sweep generator, the quality of the UE with the use of the downlink traffic channel can be determined, and the accuracy of detection of the quality of the communication system can be improved.