Modulation analysers
The Modulation Analysers category groups together instruments dedicated to the fine analysis of modulated signals used in analogue and digital communication systems. They measure essential parameters such as modulation error (EVM), frequency deviation, phase, constellation, bit error rate (BER) and amplitude and phase distortions.
In research and development, these analysers are used to validate modulation schemes (AM, FM, PM, QAM, PSK, OFDM), identify the effects of noise, non-linearities or synchronisation faults, and optimise RF and digital architectures. In production, they check the conformity of transmitters and receivers, as well as the repeatability of performance on assembly lines.
Covering extended bands from RF to microwave frequencies, the modulation analysers are based on algorithms that comply with the main communication standards. LAN, USB, GPIB or SCPI interfaces make it easy to integrate them into automated test benches, record results and trace tests.
Used in telecommunications, aeronautics, defence, automotive and embedded systems, these instruments play a key role in the reliability, robustness and compliance of modern radio links.
8902A/021
KEYSIGHT / AGILENT / HP
IF modulation analyser with high-performance measurement receiver.
53310A
KEYSIGHT / AGILENT / HP
Modulation analyser for mobile communications up to 2.5 GHz.
8200-S/10
BOONTON
Accurate, versatile modulation analyser for industrial applications.
53310A/001-030
KEYSIGHT / AGILENT / HP
2-channel pulse modulation analyser, BP=10Hz/2.5GHz.
8901A/001-002
KEYSIGHT / AGILENT / HP
Modulation analyser with bandwidth from 150KHz to 1300MHz.
8901B
KEYSIGHT / AGILENT / HP
Modulation analyser with bandwidth from 150KHz to 1300MHz.
concrete questions about Modulation analysers
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1. Why does a good EVM not always guarantee a reliable link?Because EVM is a global measurement. It can mask one-off faults such as synchronisation errors, clock instabilities or temperature- or load-dependent distortions. A correct EVM does not rule out intermittent problems in real-life conditions.
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2. At what point does constellation analysis become essential?As soon as you are working with complex modulations (QAM, OFDM, PSK) or high bit rates. Constellation allows you to immediately visualise the effects of noise, phase shifts or non-linearities that scalar measurements alone would not reveal.
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3. What is the main source of error in modulation measurements?Very often, the synchronisation reference. A wrong clock, a time misalignment or a frequency drift between the transmitter and the analyser can artificially degrade the results and lead to wrong conclusions about the system under test.
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4. Can a modulation analyser be used for field diagnostics?Yes, but with caution. On site, external disturbances, reflections or interference can influence measurements. The analyser is therefore mainly used to compare states (before/after, compliant/degraded) rather than for strict normative qualification.
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5. Why correlate modulation and conventional RF measurements?Because a modulation fault is often the consequence of an RF problem upstream: amplifier compression, excessive phase noise, inadequate filtering. By combining modulation analysis and spectral measurements, we can identify the real cause of the fault.
