‘窄带’ (zhǎi dài) is a technical term meaning ‘narrowband’, used primarily in telecommunications, signal processing, and electronics. It refers to a communication channel or frequency band with relatively small bandwidth—typically just wide enough to carry voice or low-data-rate signals, as opposed to broadband which supports high-speed data. The character 窄 (zhǎi) means ‘narrow’ or ‘limited in width’, while 带 (dài) means ‘band’ or ‘strip’, together literally forming ‘narrow band’.

This term appears frequently in engineering contexts, such as describing filter design, radio transmission systems, or IoT sensor networks where energy efficiency and interference resistance are critical. It is formal and domain-specific—rarely used in daily conversation or non-technical writing. You’ll often see it in compound terms like 窄带通信 (narrowband communication) or 窄带物联网 (narrowband IoT, NB-IoT).