spektraanalysator

Spektraanalysator is an electronic instrument used to measure and display the magnitude of an input signal as a function of frequency. It is employed to analyze spectral content, identify frequency components, measure signal strength across a band, and assess compliance with emissions standards.

The instrument typically includes a front-end RF receiver, a frequency translation stage (mixer and local oscillator), a filter or digital processing chain, and a display. In swept-tuned models the local oscillator is scanned across the frequency range and the detected amplitude is plotted versus frequency; in FFT-based analyzers the spectrum is obtained by transforming digitized samples, and real-time analyzers continuously update the spectrum to show time-varying signals.

Key specifications include frequency range, resolution bandwidth (RBW), video bandwidth (VBW), dynamic range, amplitude accuracy, and input impedance. Detectors may be peak, RMS, or average, and many instruments offer selectable reference levels and pre-attenuation. Modern units may also include features such as trace averaging, markers, and advanced logging or software control.

Typical applications are RF and microwave design and testing, wireless communications, radar, EMC/EMI testing, and audio spectrum analysis. They are used to identify harmonics, measure channel occupancy, verify modulation quality, and diagnose interference.

Historically, spectrum analyzers evolved from early swept-tuned receivers and heterodyne systems, with modern instruments integrating digital signal processing and software control to provide flexible measurement, higher dynamic range, and real-time analysis capabilities.