It provides high levels of accuracy in measurement due to vector error correction feature. It does not have source incorporated. It can demodulate and measure complex signals. It consists of source and multiple receivers and measures broadband frequency signal using techniques such as power and frequency sweep.
While doing measurements with spectrum analyzer, it is easy to place a marker on the display, but interpretation of results is difficult.
While doing measurement with network analyzer, it is hard to place a marker on the display, but interpretation of results is very easy. It houses both source and receiver and used for reflection and transmission coefficient measurement requiring both reference input, reflected and transmitted signals.
It can be used for scalar component measurements only. A VNA usually connects to a device under test through some cables and connectors. At high frequencies these connections affect the source signal and the measured signal so that the VNA can not determine the impedance properly.
For this reason a calibration of the measurement setup is necessary so that the VNA can normalize the measurement setup. There are different schemes to calibrate a VNA setup but one of the most commonly used schemes is done with an Open, Short and Load 50 Ohm element. These elements are connected in turn at the point of measurement and the VNA will measure the setup. From these three measurements the VNA has enough information to normalize the test setup away and show the impedance at the calibration point.
For gain or loss calibration, a known Through element is connected between the two measurement points that are to connect to the input and output of the device under test. While these results can be used to evaluate the matching of the device, they can not be used to calculate any kind of matching network to get a correct impedance match so the application is very limited.
A VSWR meter is an example of a scalar measurement device. While a VNA consists of a signal generator and a narrow band receiver that scan over a frequency range, a Spectrum Analyzer is only a receiver that scans over frequencies.
So a Spectrum Analyzer is a passive device that measures external signals that are present at a device or at an antenna, and can be used to measure transmitter output levels and harmonics and spurious signals.
The receiver part of a Spectrum Analyzer is optimized for these measuring functions with wider bandwidth, demodulation options etcetera. Some Spectrum Analyzers are provided with a Tracking Generator that generates a signal that is sweeping with the frequency of the Spectrum Analyzer. Spectrum analyzer do not have source incorporated. Network analyzer consists of source and multiple receivers and measures broadband frequency signal using techniques such as power and frequency sweep.
The spectrum analyzers usually will have wider range IF bandwidths compare to most of the network analyzers. Network analyzer provides higher measurement accuracy compare to spectrum analyzer due to vector error correction feature.
While doing measurement with spectrum analyzer, it is easy to place a marker on the display, but interpretation of results are difficult.
While doing measurement with network analyzer, it is hard to place a marker on the display, but interpretation of results are very easy. CDMA diff.
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