Frekuencat

Frekuencat is a term used in the field of signal analysis to describe the evolving set of frequency components that constitute a non-stationary signal. It captures how the spectral content changes over time, rather than presenting a single fixed spectrum.

Etymology: The word is a coined form that blends the Indonesian word frekuensi (frequency) with a suffix -at to indicate a collective or aggregated phenomenon; some authors use it informally to distinguish dynamic spectral content from static spectra.

Properties: Frekuencat emphasize time-varying spectral structure. They may appear as continuous spectrums in a time-frequency representation or as trajectories of spectral peaks, ridges, or instantaneous frequencies. They are sensitive to the analysis window or method used.

Analysis and measurement: Practitioners derive frekuencat from time-frequency methods such as short-time Fourier transform, wavelet transform, or other time-frequency representations. Techniques include tracking instantaneous frequency, identifying spectral ridges, and constructing spectrograms or spectrotemporal envelopes.

Applications: Frekuencat concepts are relevant in audio processing, speech analysis, radar and sonar, seismology, and communications, where signals exhibit frequency modulation, chirps, or rapidly changing spectral content.

Example: A linear chirp f(t) = f0 + kt generates frekuencat components that sweep across a range of frequencies; a spoken vowel sequence also produces distinct frekuencat trajectories as phonemes transition.

See also: frequency, spectral analysis, time-frequency analysis, spectrogram, instantaneous frequency.