Spectrum analyzer

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

CAMAC time-of-flight analyzer for molecular beam diagnostics

Abstract: Time‐of‐flight (TOF) analysis of supersonic molecular beams is accomplished by a computer‐controlled TOF analyzer incorporated into a CAMAC module. The measured arrival times are stored in a LeCroy histogramming memory module and transferred to a minicomputer for further processing. The system features four independent multichannel analyzers which can be selected by program. Each unit has 4096 24‐bit channels. Dwell times are programmable between 1 and 255 μs and the maximum counting rate is 1 MHz. The system is intended for ordinary single pulse or pseudorandom TOF analysis and can also be used in photodissociation experiments employing pulsed lasers. The calibration of the TOF analyzer is described and exemplary measurements are presented.

Elements of Electronic Instrumentation and Measurement

Abstract: 1. Introduction to Electronic Instrumentation and Measurement. 2. Some Basic Measurement Theory. 3. DC and AC Deflection Meter Movements. 4. Bridge Circuits. 5. Comparison Measurements. 6. The Basics of Digital Instruments. 7. Electronic Multimeters. 8. The Oscilloscope. 9. Signal Generators. 10. Mechanical Graphics Chart Recorders. 11. Special-Purpose Laboratory Amplifiers. 12. Operational Amplifiers. 13. Sensors, Electrodes, and Transducers. 14. Probes and Connectors. 15. Handling Signals, Sensors, and Instruments. 16. Data Converters. 17. Testing Electronic Components. 18. Measurement of Frequency and Time. 19. Measurements on Untuned Amplifiers. 20. Measurements on Tuned Circuits. 21. Antenna and Transmission Line Measurements. 22. Radio Receiver Measurements and Alignment. 23. Spectrum Analyzers. 24. Radio Transmitter Measurements. 25. IEEE-488 General Purpose Interface Bus (GPIB) Instruments. Appendix A: Integration and Differentiation. Index.

A method and apparatus employing optical emission spectroscopy to detect a fault in process conditions of a semiconductor processing system

Abstract: A method and an apparatus system feature detecting faults in process conditions of a plasma-based semiconductor processing system by sensing the spectral emissions of the plasma. As a result, the method includes sensing optical energy produced by the plasma and identifying the fault in the process conditions as a function of one or more of the plurality of spectral bands. To that end, the apparatus includes a detector in optical communication with the processing chamber to sense optical energy generated by the plasma, and a spectrum analyzer, in electrical communication with the optical detector. The spectrum analyzer resolves the spectral bands and produces information corresponding thereto. A processor is in electrical communication with the spectrum analyzer, and a memory is in electrical communication with the processor. The memory includes a computer-readable medium having a computer-readable program embodied therein that controls the system to carry-out the method.

Method and apparatus for receiving a plurality of signals having different frequency bandwidths

Abstract: A first mixer (306) shifts a first end (208) of a desired signal frequency bandwidth (206) of a desired signal (202) to an edge (508) of a first filter frequency bandwidth (502) of a first filter (312), wherein the first filter frequency bandwidth (502) is greater than the desired signal frequency bandwidth (206). Signals within a first undesired frequency spectrum (504) are attenuated by the first filter (314). A second mixer (316) shifts a second end (210) of the desired signal frequency bandwidth (206) to an edge (608) of a second filter frequency bandwidth (602) of a second filter (320) to receive the desired signal (202).

Optically Multiplexed Interferometric Fiber Optic Sensor System

Abstract: A sensor system where a number of Fabry-Perot interferometer sensors are placed in series on a single-mode fiber is discussed. Each Fabry-Perot sensor is resonant within a unique bandpass of optical wavelengths and transmits with small attenuation at all other wavelengths. Fiber Fabry-Perot interferometers with narrow-band resonances are formed by placing a matched pair of bandpass reflectors on the fiber. The sensor system has three major subsystems: a swept frequency laser, frequency selective Fabry-Perot sensors, and demodulation hardware. A grating formed by holographic process is placed in the evanescent field to produce a frequency selective reflector. Individual sensors are polled by a frequency swept laser. As the laser wavelength is scanned over the resonance bandpass of the first sensor, Fabry-Perot fringes from the first sensor are read out. As the laser continues to sweep its optical frequency, the first sensor's gratings no longer act as reflectors; the sensor becomes transparent to the optical probe. After a sufficient optical wavelength guard band, the resonance band of the second sensor is reached and fringes from the second sensor are read out. Fabry-Perot phase and fringe order information are recovered by a combination of optical and electronic signal processing. The optical processor is a second Fabry-Perot interferometer which is used as an analyzer to aid recovery of the phase information.