Spectrum analyzer

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

Combination balance analyzer and vibration spectrum analyzer

Abstract: A combination electronic device provides balance analyzing capabilities, narrow band and wide band spectrum analysis capabilities, automatic tracking filtering capabilities, precision dynamic balancing with remote phase presentation, and tracking filtering. The device presents multiple functions including: 1. A testing function; 2. A balancing function; 3. A tracking filter function; 4. A filter-out-speed function; 5. A filter-out-frequency function; 6. Spectrum analysis function. Included within the circuitry are the following components: A. a vibration signal conditioning circuit; B. an active filter having the equivalent of a four-pole response with a two-pole delay; C. a pulse-to-sine and pulse-to-consine reference signal generating circuit; D. a reference pulse conditioning circuit; E. a digital sweep circuit for spectrum analysis; F. switching circuitry to accommodate all six functions; G. adjustment means to accommodate full-scale presentation of data on X-Y recorders. The system also is adapted to accommodate multiple input sources, for example, electrical displacement signals, electrical velocity signals, electrical accelerometer signals, electrical acoustic signals.

Electrical energy analyzer

Abstract: An electrical energy analyzer including a computer for monitoring energy consumption and supporting ripple control is provided with improved A/D converter resolution by applying a 1/2 LSB square wave offset signal to the non-inverting input of a differential amplifier for amplifying a current shunt voltage. The amplifier output has limited filtering to allow a 1/2 to 1 LSB random signal to be applied to the measurement signal entering the A/D converter.

The PennBMBI: A general purpose wireless Brain-Machine-Brain Interface system for unrestrained animals

Abstract: In this paper, a general purpose wireless Brain-Machine-Brain Interface (BMBI) system is proposed. The system provides all the necessary hardware for a closed-loop sensorimotor neural interface. The system integrates a neural signal analyzer, two neural stimulators with different specifications, multiple body area sensory devices and a user-friendly computer interface. The neural signal analyzer features four channel analog frontend with configurable bandpass filter, gain stage, digitization resolution, and sampling rate. 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. Flash memory card is activated for low power operation, compressed sensing recovery verification and/or data backup. An 8-channel stimulator with high driving capability (±10 mA with compliance voltage ±22V), and a 2-channel stimulator for deep brain stimulation are included in the proposed system. Both stimulators are capable of delivering bipolar, biphasic capacitive coupled current pulses in programmable pulse shape, amplitude, width, pulse train frequency and latency. Multi-functional wireless sensor node, including an accelerometer, a temperature sensor, and a general sensor extension port has been designed. Surveillance camera is implemented for the monitoring of the animal's behavior. A userfriendly computer interface is designed to monitor, control and configure all aforementioned devices via wireless link. Wireless closed-loop operation between the sensory devices, neural stimulators, and neural signal analyzer can be configured. Bench test and in vivo experiments are performed to verify the functions and performance of the system.

Method and apparatus for signal bandwidth compression utilizing the fourier transform of the logarithm of the frequency spectrum magnitude

Abstract: A bandwidth compression system such as a digital vocoder including an analysis section employs a transducer to convert an input speech wave into an electrical signal which is then digitized by an analog to digital converter. The digitized signal is directed through a spectrum device where the magnitudes of the frequency spectrum of the input speech wave are obtained. These magnitudes are then directed to a logging circuit to obtain the logarithm of the frequency spectrum magnitudes of the input speech signal. The logged magnitudes of the frequency spectrum are then directed to a computer where the discrete Fourier transform of the logged spectrum magnitudes are obtained to form the Fourier transform of the logarithm of the frequency spectrum magnitude (FTLSM) of the input speech signal. An encoding unit selects and encodes certain ones of the FTLSM coefficients for transmission to a remote terminal for analysis. The encoded signals include pitch data and vocal tract impulse data, both of which are derived from the FTLSM signals.

Automatic linearity and frequency response tests with built-in pattern generator and analyzer

Abstract: We present a built-in self-test (BIST) approach based on a direct digital synthesizer (DDS) for functionality testing of analog circuitry in mixed-signal systems. A main contribution of this paper is the BIST-based hardware implementation and measurement of amplifier linearity (IP3) and frequency response, including both phase and gain. The approach has been implemented in Verilog and synthesized into a field-programmable gate array (FPGA), where it was used for functional testing of an actual device under test (DUT) and compared to simulation results