Final answer:
A device that boosts the signal power and rebroadcasts transmissions is called a repeater. Radio receivers use antennas to resonate at specific frequencies and amplify the signal for output. This technology underpins various wireless communication systems.
Step-by-step explanation:
A device that receives transmissions from one source, boosts the signal power, and rebroadcasts it is known as a repeater. This process is essential in ensuring that communication signals can traverse longer distances without degrading in quality. Repeaters are used in various forms of wireless communications, including radio and television broadcasting, to effectively extend the reach of the signal.
A radio receiver, when tuned to the same resonant frequency as the carrier wave, can pick up signals while ignoring other frequencies. This is achieved through the use of an antenna that resonates at a specific frequency picked up by the receiver's circuitry. The receiver then responds to changes in amplitude or frequency of the carrier wave to replicate the original signal. This replicated signal undergoes amplification to drive speakers or to be recorded.
For example, frequency modulated (FM) radio works by modulating the frequency of the carrier wave with an audio signal without altering its amplitude, allowing for high-quality audio broadcasts. Receiver antennas are designed specifically to resonate at these frequencies, ensuring clear signal reception and making communications like FM radio possible.