113results about How to "Increase signal amplitude" patented technology

The invention provides an all-fiber testing device for testing the polarization crosstalk of an optical device. The all-fiber testing device comprises a wide-spectrum light source (501), a polarizer (511), a to-be-tested polarizing device (522), an optical path correlator (530), a difference detector (550) and a photoelectric signal conversion and signal recording device (560), wherein the wide-spectrum light source (501) is connected with the to-be-tested optical fiber device (522) through the polarizer (511) and a first rotary connector (521) and is connected with the optical path correlator (530) with a polarization beam splitting Michelson structure through a second rotary connector (523); and the optical path correlator (530) is connected with the polarization difference detector (550) through a third rotary connector (541) and is connected with an interference signal detecting and processing device (560). The all-fiber testing device has the advantages of small size, high measurement accuracy, high temperature and vibration stability and the like, so that the all-fiber testing device is widely applied to high-accuracy measurement and analysis of the polarization performance of the optical device.

The invention provides a device and a method for improving polarization crosstalk measurement performance of an optical device. The device comprises a wide spectrum light source (301), a polarizer (311), a polarization device to be tested (632), an optical path correlator (640) and a polarization crosstalk detection and signal recording device (150), wherein the wide spectrum light source (301) is connected with the optical device to be tested (632) by the polarizer (311) and a first rotation connector (631) and then is connected with the optical path correlator (640) by a second rotation connector (633). By the device and the method, noise amplitude can be greatly suppressed, the sensitivity of polarization crosstalk measurement is improved, the dynamic range of polarization crosstalk measurement is expanded, and the device and the method are widely used for high-precision measurement and analysis on polarization performance of the optical device.

An apparatus and method to monitor endless belts and related belt drive systems by non-contact sensors for wear or an anomalous function, determining the state of belt drive system and detecting early stages of belt and system failure. A sensing unit featuring one or several independent sensor elements is placed near a belt of a polymer matrix with a fiber cord load bearing core to monitor several simultaneously occurring normal modes of operation. The sensor can determine soundness of the whole timing drive continuously by processing the collected signal and detecting structural damage. The collected data is processed by a microcontroller integrated with the sensor. The apparatus and method uses a non-contacting capacitor array having sensing element(s) connected to electronic circuitry that is adapted to sense the dynamic capacitance change coupled with electrocapacitive and piezoelectric effects exhibited by the belt. The sensor continuously monitors the belt during normal operation.

Disclosed is a method of making a SVGMR sensor element. In the first embodiment a buffer layer is formed between a seed layer and a ferromagnetic (FM) free layer, the buffer layer being composed of alpha-Fe₂O₃ having a crystal lattice constant that is close to the FM free layer's crystal constant and has the same crystal structure. The metal oxide buffer layer enhances the specular scattering. In the second embodiment, a high conductivity layer (HCL) is formed over the buffer layer to create a spin filter-SVGMR. The HCL layer enhances the GMR ratio of the spin filter SVGMR. The third embodiment include a pinned FM layer comprising a three layer structure of a lower AP layer, a space layer (e.g., Ru) and an upper AP layer.

A dipole antenna array comprising a ground plane, at least one dipole antenna including an active antenna element and a grounded antenna element, at least one reflector and integrated electronics, wherein the active antenna element is isolated from the ground plane and extends substantially perpendicular to the ground plane and the grounded antenna element extends in a direction substantially opposite to the active antenna element, the ground plane is contained within the area bounded by the reflector; the integrated electronics include at least one of a signal down converter and a signal up-converter, and at least some of the integrated electronics are contained in a space defined by at least one of a portion of the ground plane and a portion of the reflector.

Devices and methods for selectively reducing interference in wireless signals through field nulling and signal cancelling by signal agnostic, intrinsically stable, analytic means.

The invention relates to a multi-channel AC/DC excitation signal measuring system for a strain force sensor. A digital signal processor (DSP) is taken as the core, an AC/DC excitation mode is adoptedto select an excitation scheme with adjustable AC excitation frequency, a digital control scheme with automatic optimization of excitation frequency and modulation frequency band is adopted, a digitallow-pass filter, amplitude correction and digital signal amplification processing flow is adopted for a DC excitation mode, and a digital band-pass filter, digital signal demodulation, vector correction and digital signal amplification processing flow is adopted for an AC excitation mode, so that multi-channel and high precision signal measurement of the strain force sensor under different interference environments is realized. The system includes a hardware system and a software signal processing method. Through adoption of the multi-channel AC/DC excitation signal measuring system, the selection of the excitation mode and the signal processing flow can be automatically optimized, and the influences of excitation signal fluctuation and line parasitic parameters can be corrected, therebyrealizing high-precision measurement of single or multiple strain force sensors with up to eight measuring bridges.

The present invention provides a boron-containing gas film fast-neutron detector. The fast-neutron detector comprises a package piece having a hollow cavity; a plastic scintillator array provided in the cavity and comprising a plurality of plastic scintillator units, a gap existing between adjacent plastic scintillator units; and a boron-containing gas filled into and gas-tightly sealed in the hollow cavity, the boron-containing gas forming a boron-containing gas film in the gap between the adjacent plastic scintillator units. The fast-neutron detector of the present invention completely does not require use of scarce and expensive ³He gas, nor needs a complicated boron film coating process, improves credibility of signal coincidence, and is adapted for measurement of environment background neutrons and extensively adapted for detection of radioactive substance at sites such as customs ports, harbors and the like.

An output buffer is disclosed and includes a differential output buffer input configured for coupling to a differential output of an input circuit. The output buffer further includes an inductive voltage divider circuit coupled to the differential output buffer input, and configured to weaken a loading at the differential output of the input circuit.

A disk with an Ag reflective layer, a recording layer including elements Sb and Te, and a dielectric layer including S provided between the reflective layer and the recording layer has the problems of corrosion of the Ag reflective layer, decline of the signal quality due to insufficient heat releasing ability, and exfoliation between the layers. (1) A phase-change optical disk includes, on a transparent substrate, a recording layer in which an optically detectable reversible change between an amorphous phase and a crystalline phase can be caused by irradiation with an energy beam, a reflective layer, and a dielectric layer arranged between the recording layer and the reflective layer, wherein the main component of the dielectric layer is an oxide or a nitrooxide of Ta. (2) Between the recording layer and the dielectric layer, a layer including a nitride, an oxide, a carbide or nitrooxide of an element α (wherein α is at least one element selected from Sn, In, Zr, Si, Cr, Al, V, Nb, Mo, W, Ti, Mg and Ge) is provided.

The invention relates to a magnetic resonance multi-channel detection method and apparatus using a pre-polarization field to enhance the amplitude of a signal. The method comprises: a plurality of direct-current transmitting coils and a direct-current /alternating-current transmitting coil are set, direct currents are emitted to form a pre-polarization field, and the magnetization intensity of hydrogen protons in water is enhanced; after emission for a period of time, the direct currents are cut off, the direct-current /alternating-current transmitting coil emits an alternating current with aLarmor frequency to excite the hydrogen protons to generate a magnetic resonance phenomenon; after the alternating current is cut off, the hydrogen protons release freely-sensing attenuation magneticresonance signals, and a plurality of receiving coils and one reference coil are set to measure magnetic resonance signals and noise signals; and the alternating current amplitude is controlled to complete measurement of different pulse torques. Therefore, the signal amplitude is enhanced; the detection signal-to-noise ratio is increased; and detection on a non-layered complex water-containing structure is carried out to realize multi-dimensional magnetic resonance measurement of a uniform pre-polarization field in a high-noise environment like an environment with manual noises or serious power interference or a large tunneling area like a tunnel or mine.

An apparatus comprising: a first member including a plurality of portions separated from one another by electrical insulator material; a second member configured to form capacitors with the plurality of portions of the first member; and wherein one of the first member and the second member are configured to vibrate in response to sound waves, and a first portion of the plurality of portions is configured to provide a first output signal representative of the sound waves and a second portion of the plurality of portions is configured to provide a second output signal representative of the sound waves.

A phase shifter according to an embodiment of the present invention includes: an AC component amplifying unit; and a dividing circuit. The AC component amplifying unit has positive gain slope characteristics and deforms a waveform of an input differential clock signal to output the deformed differential clock signal. The dividing circuit includes a T-flipflop having two D latches connected in series and receives the deformed differential clock signal defoemed by the AC component amplifying unit to generate at least two output signals having a phase difference of 90 degrees with a frequency of ½ of the deformed differential clock signal.

A system and method for generating, enhancing, and detecting the amplitude and phase modulation of a laser under a condition of self-mixing is provided. The system may comprise a laser and a detector to extract the characteristic self-mix signal, which is then interpreted using algorithms implemented in hardware or software. In the case of the laser being a Vertical Cavity Surface Emitting laser (VCSEL), the output signal can be detected by monitoring the surface light emission by means of a beam splitter, or in some embodiments as emission from the bottom surface of the laser. In some embodiments, the system may further comprise a wavelength filter such as an etalon in the signal path.

The invention relates to a weak signal detection method for multi-scale noise-regulated stochastic resonance, belonging to the signal processing field. Aiming at the problem that the output of generalstochastic resonance system does not resonate at multiple frequencies at the same time, the influence mechanism of multi-scale noise reduction on stochastic resonance is studied, and a wavelet packettransform (WPT)-based method for noise-tuned stochastic resonance (NTSR) is proposed. The noise inherent in the signal is tuned into multi-scale noise by WPT, so that the noise can be tuned more carefully. The method is based on wavelet packet transform (WPT). The new method is used to overcome the limitation of the traditional parameter adjustment method, stochastic resonance detection based onWPT multi-scale noise adjustment has a good performance in rotating machinery multi-transient fault signal detection, which has a certain guiding significance and practical value. The method can further improve the output signal-to-noise ratio and achieve multi-frequency detection.

The invention provides a system and a method for testing stray radiation of a radio frequency transmitter. The system is a near-field test system, and a test field is a microwave anechoic chamber; a servo system is a one-axis precision rotary table installed in the microwave anechoic chamber, and an antenna of a radio frequency transmitter to be tested is arranged on the precision rotary table. Aradio frequency subsystem comprises a vector network analyzer. The vector network analyzer receives radiation signals of a radio frequency transmitter antenna to be tested through a test probe to complete amplitude and phase parameter test of the radio frequency transmitter antenna to be tested. The test method adopts a field test method. According to the invention, spherical near-field sampling of an electromagnetic field is realized by using a one-axis rotary table in cooperation with a probe array.