wideband

Wideband refers to systems, devices, or signals that occupy a relatively broad portion of the frequency spectrum. The term is used across fields such as radio communications, audio technology, radar and sonar, and measurement instrumentation. It is commonly contrasted with narrowband, which covers a small frequency range around a carrier, and with broadband in everyday language, where the emphasis is often on high data rates rather than a specific fractional bandwidth.

In communications, wideband typically means a channel or system with a large fractional bandwidth, often tens of percent or more of the center frequency. Wideband designs support high data rates and fine time resolution, but they require wideband filters, receivers with flat responses over broad frequencies, and advanced signal processing. They can be more susceptible to interference and dispersion and may demand more complex calibration and design.

In audio, wideband refers to audio bandwidth greater than traditional narrowband speech, improving fidelity. Common wideband implementations extend beyond the 300–3,400 Hz telephone range, with higher sampling rates such as 16 kHz or 32 kHz to preserve more of the audible spectrum, including higher frequencies up to several kilohertz.

In radar, sonar, and instrumentation, wideband indicates signals or systems that operate over broad spectral ranges to achieve high time or range resolution. Wideband antennas and transceivers enable multi-band operation and rapid spectrum sensing. Measurement instruments, such as wideband oscilloscopes and spectrum analyzers, are designed to capture signals across wide frequency spans.

Trade-offs of wideband systems include increased hardware complexity, higher power consumption, greater susceptibility to noise and interference, and the need for precise calibration to maintain flat response over the entire band.