Many other devices also use rf amplifiers, such as radios, navigational devices, and communications systems. Almost any device that uses broadcast, or transmitted, information will use an rf amplifier. Therefore, any device that uses frequencies between 10 kilohertz and 100,000 megahertz will most likely use an rf amplifier. Before you study the details of video and rf amplifiers, you need to learn a little more about the Frequency response of an amplifier and frequency-response curves. In chapter 1 of this module you were shown the frequency-response curve of an audio amplifier.
Every amplifier has a frequency-response curve associated with it.
The amplifier for which the frequency-response curve is created is tested at various frequencies. For each of these frequencies, the output is measured and marked on a graph. When points have been plotted for all of the frequencies tested, the points are connected to form the frequency-response curve. The shape of the curve represents the Frequency response of the amplifier. For frequencies outside the band, the amplifier gain will be much lower.