Accession Number : ADA185912

Title :   Signal-to-Noise Ratio Requirements for Half-Wave and Full-Wave Nonlinear Detectors with Arbitrary Power Laws, Sampling Rates, Input Spectra, and Filter Characteristics

Descriptive Note : Technical rept.

Corporate Author : NAVAL UNDERWATER SYSTEMS CENTER NEW LONDON CT

Personal Author(s) : Nuttall, Albert H

PDF Url : ADA185912

Report Date : 10 Jun 1986

Pagination or Media Count : 124

Abstract : The output signal-to-noise ratio of a signal detection system consisting of a sampler, a nonlinear rectifier, and a low-pass filter is evaluated generally, for arbitrary half-wave or full-wave nu-th law rectifiers, sampling rates, input spectra, input signal-to-noise ratio, and filter characteristics. The usual assumption of a long averaging time, relative to the inverse bandwidth of the input spectrum, is not made, thereby affording an explanation of the anomalous behavior of a half-wave rectifier for low-Q input spectra. A pitfall of employing the long averaging time assumption is illustrated via numerical example. A simple recurrence for the half-wave and full-wave nu-th law rectifier coefficients allows for a very fast and efficient high-order series evaluation of the output signal-to-noise ration for any value of nu. For moderate-or-large-Q input spectra, the possibility of using deliberate undersampling with no loss of performance is illustrated. The use of a half-wave rectifier generally requires a higher sampling rate than does a symmetric full-wave rectifier; also the performance is somewhat poorer for the half-wave rectifier, and in some cases, significantly so.

Descriptors :   *DETECTORS, *FULL WAVE RECTIFIERS, *LOW PASS FILTERS, *NONLINEAR SYSTEMS, ANOMALIES, BANDWIDTH, BEHAVIOR, FILTERS, HIGH RATE, INPUT, INVERSION, LONG RANGE(TIME), LOSSES, MEAN, OUTPUT, RATES, RECTIFIERS, REQUIREMENTS, SAMPLING, SIGNAL TO NOISE RATIO, SIGNALS, SPECTRA, SYMMETRY

Subject Categories : Cybernetics
      Miscellaneous Detection and Detectors

Distribution Statement : APPROVED FOR PUBLIC RELEASE