demodulatora

Demodulatora, usually called a demodulator, is a device or circuit that recovers the original information-bearing signal from a modulated carrier. It is a key component in receivers and data links, converting a transmitted modulation into a baseband or lower-frequency signal suitable for processing, display, or storage. The demodulation process follows modulation and varies with the modulation scheme used at the transmitter.

In analog demodulation, the goal is to extract the baseband signal from continuously varying carrier properties. Common examples include amplitude modulation (AM), where an envelope detector or synchronous detector recovers the audio, and frequency modulation (FM) or phase modulation (PM), where discriminators, ratio detectors, or phase-locked loops are used to recover the instantaneous frequency or phase corresponding to the original signal. Each method aims to preserve fidelity while rejecting noise and distortion within a specified bandwidth.

Digital demodulation handles symbols rather than continuous waveforms. Here the demodulator detects the transmitted digital symbols, using coherent detection with carrier recovery or non-coherent detection when a carrier reference is unavailable. Schemes such as binary or multi-level ASK, FSK, PSK, and QAM are common, often accompanied by channel equalization and error-correcting codes. Digital demodulators rely on sampling, symbol timing, and decision logic, and may operate entirely in the digital domain using software or dedicated hardware.

Implementation considerations include front-end filtering, downconversion, carrier recovery, and decision circuitry. Performance is influenced by noise, interference, bandwidth, modulation order, and the quality of the local oscillator. Demodulators are found in radio receivers, television sets, data modems, and wireless communication systems, forming a foundational element of modern communications.