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Pulse Amplifiers differ from Pulse Modulated Amplifiers, in that they are designed to amplify pulses, as opposed to being turned off and on by a pulse. Many of MITEQ's amplifiers can be used for pulse amplification, but only selected models appear in this section. Some designs specifically handle 12.5 Gb/S NRZ or RZ data strings, either linearly or saturated.
In order to determine whether a particular amplifier will amplify and maintain the pulse shape, you need to consider the following: The 3 dB bandwidth (preferably the 1 dB BW for some applications) must be wide enough to meet the required rise and fall times. For a normal amplifier, the approximate rise-time = 0.35/(3dB BW); however, if a sharp filter is used the rise and fall times can be roughly doubled.
To be a good Pulse Amplifier, the phase linearity (group delay variation) also must be quite good without resonances or sharp variations. This goes along with a wide band and a relatively flat frequency response. To limit the overshoot of a square pulse, the frequency response at the third and higher harmonics should be equal to or less than that of the fundamental Fourier series component. Bessel filters are sometimes used to achieve this. |