Vector Network Analyzers - Get Started with the Fundamentals
February 12, 2019 - Rohde & Schwarz USA
(R&S USA) has published an application note entitled, "Group Delay Measurements with Signal and Spectrum Analyzers."
- The available bandwidth of RF channels are often limited by the bandpass characteristic
of filters, amplifiers and mixers. Detecting amplitude flatness and phase distortion
is crucial in characterizing the quality of a transmission channel. The amplitude
flatness within the used bandwidth may have an influence on the signal quality.
Knowledge about phase distortion is essential to maintain low bit error rates in
data transmissions and VNAs (Vector Network Analyzer) commonly perform amplitude
flatness and phase distortion measurements.
Phase distortions in a transmission channel are determined using group delay
measurements, they must be as low as possible to maintain good signal quality. Vector
network analyzers are normally used to characterize the group delay variations as
a measure of phase distortion.
This application note provides basic information
about the concept of a group delay measurement with spectrum analyzers and signal
generators, and how this method simplifies the test setup and improves the measurement
Measurement examples show the limiting factors of this approach and help the
user to understand and avoid some limitations of this method. In addition the test
results are compared to those generated with vector network analyzers.
About Rohde & Schwarz
Founded more than 80 years ago, Rohde & Schwarz is one of the world's leading
manufacturers of information and communications technology products for
professional users. Initially focusing on RF engineering and RF applications in
test and measurement, radiocommunications and broadcasting, the company has
continually expanded its fields of activity over the past decades . In the
meantime Rohde & Schwarz has also become one of Germany's largest manufacturers
of IT security products.
Rohde & Schwarz USA, Inc.
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Europe, Africa, Middle East
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+1 888 837 8772
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+86 800 810 8228 or +86 400 650 5896
Posted February 15, 2019