enow.com Web Search

Search results

  1. Results from the WOW.Com Content Network
  2. Intermodulation - Wikipedia

    en.wikipedia.org/wiki/Intermodulation

    The intermodulation between frequency components will form additional components at frequencies that are not just at harmonic frequencies (integer multiples) of either, like harmonic distortion, but also at the sum and difference frequencies of the original frequencies and at sums and differences of multiples of those frequencies.

  3. Sound amplification by stimulated emission of radiation

    en.wikipedia.org/wiki/Sound_amplification_by...

    The conversion between real space and k-space is a mathematical transformation called the Fourier transform and thus k-space can be also called Fourier space. We note that, the difference in energy of the photon lasing levels has to be at least smaller than the Debye energy in the semiconductor.

  4. Amplifier - Wikipedia

    en.wikipedia.org/wiki/Amplifier

    The frequency range handled by an amplifier might be specified in terms of bandwidth (normally implying a response that is 3 dB down when the frequency reaches the specified bandwidth), or by specifying a frequency response that is within a certain number of decibels between a lower and an upper frequency (e.g. "20 Hz to 20 kHz plus or minus 1 ...

  5. Frequency modulation - Wikipedia

    en.wikipedia.org/wiki/Frequency_modulation

    If the frequency deviation is held constant and the modulation frequency increased, the spacing between spectra increases. Frequency modulation can be classified as narrowband if the change in the carrier frequency is about the same as the signal frequency, or as wideband if the change in the carrier frequency is much higher (modulation index ...

  6. Chirp spectrum - Wikipedia

    en.wikipedia.org/wiki/Chirp_spectrum

    Unless θ (t) is a constant, the point in time t s at which the phase is stationary will vary according to the instantaneous frequency ω s. Expressing the difference between (ω s-ω 0).t and θ (t) as a Taylor series about the time t s, but discarding all but the first three terms (of which the second term is zero, here), the Fourier integral ...

  7. Non-contact atomic force microscopy - Wikipedia

    en.wikipedia.org/wiki/Non-contact_atomic_force...

    Change in resonant frequency of AFM sensor driven off resonance (amplitude modulation mode) causes a change in amplitude. Amplitude modulation was one of the original modes of operation introduced by Binnig and Quate in their seminal 1986 AFM paper, [5] in this mode the sensor is excited just off resonance. By exciting the sensor just above its ...

  8. Lock-in amplifier - Wikipedia

    en.wikipedia.org/wiki/Lock-in_amplifier

    The operation of a lock-in amplifier relies on the orthogonality of sinusoidal functions.Specifically, when a sinusoidal function of frequency f 1 is multiplied by a sinusoidal function of another frequency f 2 and integrated over a time much longer than the period of the two functions, the result is close to zero.

  9. Frequency - Wikipedia

    en.wikipedia.org/wiki/Frequency

    The period (symbol T) is the interval of time between events, so the period is the reciprocal of the frequency: T = 1/f. [2] Frequency is an important parameter used in science and engineering to specify the rate of oscillatory and vibratory phenomena, such as mechanical vibrations, audio signals , radio waves, and light.