Spectrum analyzer

About: Spectrum analyzer is a research topic. Over the lifetime, 12217 publications have been published within this topic receiving 101851 citations.

Multi-component infrared analyzer

Abstract: A multi-component nondispersive infrared correlation spectrometer for selectively analyzing for a plurality of gases of interest in a gaseous mixture utilizes a rotating filter wheel containing filter systems corresponding to each gas of interest sought. Each filter system contains an ordered pair of filters to sequentially create filtered reference and analysis paths for each gas of interest between a source of infrared radiation and a detector. Special synchronization and signal analysis systems are provided to produce an output signal for each gas of interest. These systems are coordinated with the rotation of the filter wheel in a manner which allows a plurality of gases of interest to be analyzed with simultaneous output.

Quick connect diagnostic apparatus and method for a vehicle cooling system

Abstract: A quick connect diagnostic apparatus for the cooling system of a vehicle engine includes first, second and third temperature sensors which are configured to attach to liquid hoses which circulate cooling liquid throughout the engine, the first sensor attaching to a hose directly from the engine, the second and third sensors attaching to input and output hoses, respectively, connected to the radiator. The sensors are housed within a cuff structure which is wrapped around the hoses to detect the fluid temperatures within the hoses. Each sensor is connected to an analyzer which compares the first signal to a temperature threshold signal, compares the first signal to the second signal to generate a first difference signal which is then compared to a thermostat threshold signal, and compares the second and third signals to produce a second different signal which is compared to a radiator threshold signal. The analyzer utilizes the various difference signals and temperature signals to produce output signals indicative of the engine temperature, and the operational status of the radiator and thermostat. Output circuitry electrically coupled to the analyzer provides humanly perceptible outputs in response to the output signals from the analyzer.

Optical spectrometer at the nanoscale using optical Yagi-Uda nanoantennas

Abstract: Here we present and analyze an optical spectrum analyzer at the nanometer scale that is able to distribute different frequency contents of the radiation of an optical dipole source into different directions in the space. The spectrum analyzer is composed of arrays of optical Yagi-Uda nanoantennas, forming relatively narrow radiation patterns operating at different frequencies. The optical Yagi-Uda nanoantennas composed of plasmonic core-shell nanoparticles are used as an example of building blocks for this idea in our study. Narrow radiation beams in such antenna arrays are realized by tailoring the scattering phase of the nanoparticles. The sensitivity of such an antenna array to the operating wavelength and the angular distribution of the radiation pattern, which is essential for the operation of the spectrum analyzer proposed here, is studied theoretically. The chromatic dispersion and the angular variation of the radiation pattern of such an optical spectrum analyzer are discussed in detail.

The PennBMBI: Design of a General Purpose Wireless Brain-Machine-Brain Interface System

Abstract: In this paper, a general purpose wireless Brain- Machine -Brain Interface (BMBI) system is presented. The system integrates four battery-powered wireless devices for the implementation of a closed-loop sensorimotor neural interface, including a neural signal analyzer, a neural stimulator, a body-area sensor node and a graphic user interface implemented on the PC end. The neural signal analyzer features a four channel analog front-end with configurable bandpass filter, gain stage, digitization resolution, and sampling rate. The target frequency band is configurable from EEG to single unit activity. A noise floor of 4.69 $\mu{\rm Vrms}$ is achieved over a bandwidth from 0.05 Hz to 6 kHz . Digital filtering, neural feature extraction, spike detection, sensing-stimulating modulation, and compressed sensing measurement are realized in a central processing unit integrated in the analyzer. A flash memory card is also integrated in the analyzer. A 2-channel neural stimulator with a compliance voltage up to $\pm$ 12 V is included. The stimulator is capable of delivering unipolar or bipolar, charge-balanced current pulses with programmable pulse shape, amplitude, width, pulse train frequency and latency. A multi-functional sensor node, including an accelerometer, a temperature sensor, a flexiforce sensor and a general sensor extension port has been designed. A computer interface is designed to monitor, control and configure all aforementioned devices via a wireless link, according to a custom designed communication protocol. Wireless closed-loop operation between the sensory devices, neural stimulator, and neural signal analyzer can be configured. The proposed system was designed to link two sites in the brain, bridging the brain and external hardware, as well as creating new sensory and motor pathways for clinical practice. Bench test and in vivo experiments are performed to verify the functions and performances of the system.

The new high resolution ultra small angle neutron scattering instrument at the high flux reactor in Grenoble

Abstract: In 1998, the combined Interferometer and Ultra Small Angle Neutron Scattering (USANS) instrument S18 at the 58 MW High Flux Reactor at the Institute Laue-Langevin in Grenoble (France) started operation. The instrument has been upgraded to allow more advanced neutron optics experiments for fundamental, nuclear and condensed matter physics. The new supermirror guide along with the two channel cut silicon perfect crystals, configured as an advanced high resolution Bonse-Hart camera, provides optimal intensity conditions. A large range of wavelengths is accessible by variations of the Bragg angle and by using different reflecting planes of a properly cut silicon monochromator block in combination with different channel-cut analyzer crystals. The fine adjustment analyzer system is achieved by an advanced piezo drive, which has an accuracy of 0.036 seconds of arc. The basic features of the USANS camera, which takes advantage of a new tail suppression method, and the results of various test measurements concerning intensities, long term stability and the accessible wavelength range will be presented. A high resolution position sensitive detector can either be used to analyze beam profiles or to perform neutron radiography experiments.