Modulation sine wave

VSFFM, ISFFM - Used to create a frequency-modulated sine wave. 

The purpose of this chapter is to describe the principles of signal analysis/synthesis based on a sine-wave representation and to describe its many speech and music applications. As stated, an important feature of the sinusoidal representation is that the aforementioned sound components can be expressed approximately by a sum of amplitude- and frequency-modulated sine waves. Moreover these sound components, as well as the source and filter contribution to their sine-wave representation, are separable by means of a sine-wave-based decomposition. This separability property is essential in applying sinusoidal analysis/synthesis in a number of areas. 

Under these conditions, the magnetic field (B0+BrSimp) can be considered to be effectively constant. The mechanism whereby the magnetic field modulation is transformed to RF power modulation is illustrated in Fig. 5. The field modulated sine wave sinaW is converted by the non-linear lineshape to a complex signal S(B) that is a superposition of the fundamental modulation frequency com and a large... 

Figure 10.11. Simple FM (one earrier and one modulator sine wave) synthesis.

A shift or translation of f(r) by results in a modulation of the Fourier coefficients by exp(-ycofo). Without shift f(r) is transformed into F(fo). After a shift by tQ, fit - tg) is transformed into exp(-ja)tQ) F(sine wave) of the Fourier coefficients. The frequency cotg of the... 

The structure of iodine at four different pressures. The outlined face-centered unit cell in the 30-Gpa figure corresponds to that of a (distorted) cubic closest-packing of spheres. At 24.6 GPa four unit cells of the face-centered approximant structure are shown the structure is incommensurately modulated, the atomic positions follow a sine wave with a wave length of 3.89 x c. The amplitude of the wave is exaggerated by a factor of two. Lower left Dependence of the twelve interatomic contact distances on pressure... 

Fig. 9.16 A sine wave modulation of the etching current produces an array of macropores with a corresponding modulation of diameter.

The performance of the temperature controller was measured in the tracking mode. Figure 6.18 shows a graph, where the temperature of one of the three microhotplates is kept at a constant temperature of 300 °C, the temperature of the second microhotplate is modulated using a sine wave of 10 mHz, while rectangular temperature steps of 150 °C, 200 °C, 250 °C, 300 °C, and 350 °C have been appHed to the third microhotplate. Temperature measurements on one of the hotplate that has been operated at constant temperature in the stabihzation mode showed a variation of less than 1 °C, even though the temperature of the neighboring hotplates was, at the same time, modulated dynamically (sine wave, ramp, steps). This is a consequence of the individual hotplate temperature control, without which thermal crosstalk between the hotplates would have been clearly detectable. The power dissipation of the chip is approximately 190 mW, when all three hotplates are simultaneously heated to 350 °C. In the power-down mode, the power consumption is reduced to 8.5 mW. 

The fundamental performance parameter of any detector is its noise equivalent power (NEP). This is simply the input irradiance power necessary to achieve a detector output just equal to the noise. This NEP is dependent on a number of detector and signal variables such as modulation frequency and wavelength (the input signal is defined as sine wave modulated monochromatic light), and detector area, bandwidth and temperature. 

Fig. 21. Sine-wave modulation observed above Tjj = 18.5 K in NpAs2- (Rossat-Mignod et al. )...

For a finite sampling interval A<5, more than one superposition of cosine/sine waves can give rise to the recorded interferogram. For the transformed spectrum to be unique, the sampling interval A<5 must be sufficiently small to detect modulations in the interferogram due to the shortest wavelength present in the spectrum, the so-called Nyquist criterion [66] ... 

The graphical representation of this protocol is shown schematically in Fig. 10.15. Signals from two amperometric electrodes, representing channel 1 (blue) and channel 2 (red) detect to electroactive species, which is delivered to them with frequency modulation of, for example, 1 Hz. The experiment is performed in the benchtop fluid setup shown in Fig. 10.16. The first interesting observation is the presence of higher harmonics in the coherence spectrum. They arise as the effect of nonsinusoidal modulation. A pure sine wave would transform to the frequency domain as a single line. Any other waveform of the same frequency will contain higher harmonics in the spectrum. 

A time-dependent quantity X t) responding to the sine wave modulation of some low level perturbation dKcos a>t and frequency a>/2n, is generally written in linear conditions as ... 

In a particular case of a sine wave modulation of low amplitude, a similar relation can be written with the complex quantities. Differentiating Eq. (1-1) for each frequency and considering the fact that /, E or Q are independent variables two by two, one obtains ... 

S. Brukenstein et al. proposed in 1973 [5] this technique as an alternative to the sine-wave modulation technique. Their approach was based on the Benton s analysis of fluid flow near an impulsively started disk from rest [61]. They assumed that the... 

Equation (9.5) can be viewed as first a modulation of the window to frequency cq thus producing a bandpass filter w(n)eJ an followed by a filtering of x(n) through this bandpass filter. The output is then demodulated back down to baseband. The temporal output of the filter bank can be interpreted as discrete sine waves that are both amplitude- and phase-modulated by the time-dependent Fourier transform. 

Thus the output of each filter can be viewed as an amplitude- and phase-modulated complex sine wave... 

In addition to FM signals with nested modulators, Justice also considered a class of signals modeled by a harmonic sum of sine waves with a slowly varying amplitude, typical of many speech and music sounds... 

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