It is the invention of negative feedback which makes highly linear amplifiers possible.

However, external linear amplifiers are often used illegally.

Similar matching networks are used in other equipment (such as linear amplifiers) to transform impedance.

The matching SB-200 linear amplifier completed the line for 1965.

"And many of these have their power boosted illegally by linear amplifiers."

If it goes through a linear amplifier, the result continues to be pure (but may acquire a phase shift).

As with the linear amplifiers, they may preserve the phase and keep the uncertainty low, but there are exceptions.

However, care must be taken to use a highly linear amplifier in order to avoid adding excessive noise to the signal.

Other types of linear amplifier are used in audio and laboratory equipment.

A linear amplifier of the proper frequency is required for this job.