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Peak-to-peak amplitude (abbreviated p–p or PtP or PtoP) is the change between peak (highest amplitude value) and trough (lowest amplitude value, which can be negative). With appropriate circuitry, peak-to-peak amplitudes of electric oscillations can be measured by meters or by viewing the waveform on an oscilloscope .
The peak-to-average power ratio (PAPR) is the peak amplitude squared (giving the peak power) divided by the RMS value squared (giving the average power). [1] It is the square of the crest factor. When expressed in decibels, crest factor and PAPR are equivalent, due to the way decibels are calculated for power ratios vs amplitude ratios.
Depending on context, wave height may be defined in different ways: For a sine wave, the wave height H is twice the amplitude (i.e., the peak-to-peak amplitude): [1] =.; For a periodic wave, it is simply the difference between the maximum and minimum of the surface elevation z = η(x – c p t): [1] = {()} {()}, with c p the phase speed (or propagation speed) of the wave.
In the above formula, P is measured in units of power, such as watts (W) or milliwatts (mW), and the signal-to-noise ratio is a pure number. However, when the signal and noise are measured in volts (V) or amperes (A), which are measures of amplitude, [note 1] they must first be squared to obtain a quantity proportional to power, as shown below:
In other words, it is the width of a spectrum curve measured between those points on the y-axis which are half the maximum amplitude. Half width at half maximum (HWHM) is half of the FWHM if the function is symmetric. The term full duration at half maximum (FDHM) is preferred when the independent variable is time.
Peak values can be calculated from RMS values from the above formula, which implies V P = V RMS × √ 2, assuming the source is a pure sine wave. Thus the peak value of the mains voltage in the USA is about 120 × √ 2, or about 170 volts. The peak-to-peak voltage, being double this, is about 340 volts.
In the important case that E(t) is sinusoidally varying at some frequency with peak amplitude E peak, E rms is /, with the average Poynting vector then given by: =. This is the most common form for the energy flux of a plane wave, since sinusoidal field amplitudes are most often expressed in terms of their peak values, and complicated problems ...
The peak amplitude and the frequency of the carrier signal are maintained constant, but as the amplitude of the message signal changes, the phase of the carrier changes correspondingly. Phase modulation is an integral part of many digital transmission coding schemes that underlie a wide range of technologies like Wi-Fi , GSM and satellite ...