| There are many similarities between radio frequency | | | | transmitters to amplify radio frequency signals before |
| amplifiers and audio frequency amplifiers, but there | | | | modulation, in receivers to amplify received radio |
| are also many differences. Radio frequency amplifiers | | | | frequency signals, and as frequency multipliers. The |
| perform the same amplifying functions at radio | | | | two types of radio frequency voltage amplifiers are |
| frequencies as do audio frequency amplifiers at audio | | | | the standard broadband, multi frequency radio |
| frequencies. Voltage and power amplifiers are used in | | | | frequency amplifiers and the intermediate frequency |
| both types of systems. But since the signal | | | | amplifiers, a fixed frequency radio frequency amplifier |
| frequencies are very different, and radio frequency | | | | commonly used in super heterodyne receivers. The |
| amplifiers require higher selectivity than audio | | | | intermediate frequency amplifier follows the mixer |
| frequency amplifiers, the radio frequency amplifiers | | | | stage and precedes the detector stage. In the |
| normally make use of tuned circuits or selective | | | | receiver the intermediate frequency amplifies a |
| filters to achieve the required selectivity. | | | | narrow band of frequencies between audio |
| Radio frequency voltage amplifiers are used in | | | | frequencies and radio frequencies ranges. |