Spectrum analysis.

A spectrum analyzer detects the signals present in a selected spectrum range.
A signal analyzer, also known as a vector signal analyzer (VSA), is used for the demodulation and analysis of signals with complex, digital modulation. A signal analyzer records signals at a fixed center frequency and uses filters to set the frequency measurement range (bandwidth) for the spectrum display. A spectrum analyzer, on the other hand, works over a larger frequency range. Most VSAs also have a spectrum analysis mode, which is more suitable for detecting interference signals. This increases the frequency measurement range of the detected signal.

The dynamic range generally describes the maximum and minimum values that a measuring device can record. In a spectrum analyzer designed for the simultaneous detection of multiple signals, the dynamic range corresponds to the ability to detect a weak signal in the presence of a strong signal. The dynamic range of a spectrum analyzer is therefore the ratio of a larger signal to a smaller signal (specified in dB). It is one of the fundamental performance criteria of a spectrum analyzer.

The dynamic range is limited by the inherent noise of the analyzer with regard to the weaker signal. The inherent noise is specified using the displayed average noise level (DANL, in dBm), normalized to a 1 Hz resolution bandwidth. A preamplifier reduces the averaged displayed noise so that weak signals can be better detected. However, this reduces the dynamic range.

All electronic devices must be checked for compliance with the applicable standards (VDE / EN) to determine whether they emit electromagnetic radiation into the environment and how high these values are at different frequencies. One suitable measuring device for EMC tests is the spectrum analyzer. It can be used to determine at which frequency the radiation occurs, how high the power level of this frequency is and whether a permissible limit value is exceeded. The spectrum analyzer is used for pre-compliance testing and EMC conformity tests.

A spectrum analyzer for specific areas of application such as EMC tests has, among other things, the corresponding limit value and tolerance masks that are specified in the legal regulations for standard-compliant EMC tests. The user can see directly whether a signal is within the tolerance limit and whether a design complies with the required standards.

The frequency components are displayed as an amplitude spectrum. This allows the signal quality, interference and unwanted frequencies to be detected and analyzed.

A spectrum analyzer is used for a wide range of applications. The range of available models and performance parameters is therefore correspondingly wide. The range extends from low-cost analyzers with a frequency range from 2 Hz to portable (handheld) and universal mid-range devices through to fully equipped 110 GHz spectrum analyzers. A high-quality signal and spectrum analyzer is characterized, among other things, by outstanding signal integrity, high measurement speed and sensitivity as well as low phase noise.

Spectrum analysis is a technique for analyzing and displaying signals in the frequency range. In terms of electromagnetic compatibility (EMC), it is important for identifying and evaluating faults and interference in electronic systems. This ensures that the regulatory requirements are met.

Spectrum analysis enables engineers to identify the frequency ranges in which interference occurs and thus localize the causes of EMC problems. By analyzing the spectrum, engineers can understand the type of interference, its frequency, amplitude and changes over time, which is helpful in troubleshooting and resolving EMC issues.