What describes the functionality of energy-efficient receivers activated by incoming signals?

Wakeup receivers are specifically designed to enhance energy efficiency in communication systems. Their primary functionality is to remain in a low-power state until they detect an incoming signal, at which point they "wake up" to process the signal. This capability significantly reduces power consumption during idle periods because the wakeup receiver does not consume substantial energy when no signals are being transmitted.

The operational design of wakeup receivers is highly beneficial in scenarios where continuous connectivity is not needed, allowing devices to conserve battery life while still being responsive to potential communications. This makes them particularly useful in low-power wireless applications and Internet of Things (IoT) environments, where managing battery life is crucial for device longevity.

Other types of receivers, such as active or passive receivers, do not share this same energy-efficient characteristic. Active receivers typically remain on or consume power to be ready for communication, while passive receivers lack the capability to process signals autonomously and may not provide the same level of energy conservation.