Gain bandwidth

An additional consideration is the gain-bandwidth product specification of the operational amplifier used as the error amplifier. If the Bode character-... 

Another limiting factor is the bandwidth of the op-amp. On the factory specifications, the commonly used indicator is the gain-bandwidth product. The nominal dc gain is valid up to a cutoff frequency / which is typically 10 Hz. Above that frequency, the gain g is inversely proportional to the frequency. The product of gain and frequency, the gain-bandwidth product/a is typically 1 MHz. The input impedance of the amplifier increases with frequency ... 

EXERCISE 5-9 Plot the gain bandwidth of the amplifier in the previous example versus the feedback resistor RF. SOLUTIOIl Rerun the simulation with more detail in the Parametric Sweep ... 

High gain-bandwidth at low supply euccant (>10MHz/aA)... 

Where Avbw is the total oscillating bandwidth. The shortest pulses are therefore generated by the widest frequency distributions, that is, by arranging for a broad gain bandwidth. Only those frequencies in the emission spectrum of the laser material that can be maintained above the lasing threshold will participate in Avbw Dye lasers and some solid-state lasers (titanium-sapphire) have broad spectral outputs and can produce pulse widths significantly lower than 1 ps. Gas lasers have much narrower bandwidths and typically have pulse widths closer to 100 ps. The solid-state Nd YAG laser is intermediate at near 30 ps. 

The eontribution to the drain current from the gate drain capacitance was found to be small for frequencies within the unity-gain bandwidth and is therefore ignored. The gate current becomes ... 

The drain-source capacitance Qs can be neglected since only a constant drain voltage Vis is applied. The total gate capacitance is given by Cg = tot Q with yf tot ihs total gate area. The unity-gain bandwidth can now be calculated from Eqs. (8), (10) and (12) ... 

Gain bandwidth Type, gain saturation Homogeneous saturation flux Decay lifetime (lower level) Inversion density Small signal gain coefficient Pump power density Output power density Laser size (diameter length) Excitation current/voltage Excitation current density Excitation power Output power Efficiency... 

A laser cavity tends to select specific wavelengths (Fig. 5) within the normal gain bandwidth of the laser gain medium... 

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