Terminology » RF Basics » RF Vector Signal Generator (VSG) vs Vector Signal Analyzer (VSA)

RF Vector Signal Generator (VSG) vs Vector Signal Analyzer (VSA)

rf signal generator signal analyzer vsg vsa

In the field of RF and wireless communication, both the RF Vector Signal Generator (VSG) and the Vector Signal Analyzer (VSA) are critical tools for ensuring system performance and accuracy. While a VSG is designed to generate RF signals for testing and simulation, a VSA focuses on capturing and analyzing signals for troubleshooting and validation. Understanding the key differences, features, and applications of these devices can help engineers select the right tool for their specific needs. This comparison will provide a detailed overview of VSG and VSA, highlighting their unique roles in RF signal processing.

RF VSG

It is basically a Vector Signal Generator which generates baseband IQ vectors for various modulated signals as per wireless standards viz. WLAN, WiMAX, Zigbee, GSM, CDMA, LTE and more. It is available in various flavors, in different ways as per user need. Following are well known deliverables provided by Test and Measurement Companies such as Agilent, National Instruments, R&S, Anritsu, Litepoint and more.

  • Offline VSG Application: It generates IQ vector in various formats (floating point, fixed point and more). Can be saved in a file and the same can be played on realtime RF instrument or can be loaded to any VSA (Vector Signal Analyzer) application in offline mode manually.

  • RF VSG: It generates modulated RF vector so that it can be used to cross check realtime DUT’s Receiver’s performance/functionality. Most of the RF VSGs provides facility to load external IQ file to be played and will in turn generates modulated RF signal.

RF VSA

It is basically vector Signal Analyzer which analyzes baseband IQ vector of various modulated signals as per wireless standards viz. WLAN, WiMAX, Zigbee, GSM, CDMA, LTE and more. It is available in various flavors i.e. in different ways as per user need. Following are well known deliverables provided by Test and Measurement Companies such as Agilent, National Instruments, R&S, Anritsu, Litepoint and more.

  • Offline VSA Application: It analyzes IQ vector in various file formats (floating point, fixed point and more). Decoded data can be saved in a file and compared with standard expected data.

  • RF VSA: It generates analyzes RF vector so that it can be used to cross check realtime DUT’s Transmitter’s performance/functionality.

Comparison between RF VSG and VSA

The following table highlights the key differences and roles of VSGs and VSAs in RF and wireless communication systems.

FeatureRF Vector Signal Generator (VSG)Vector Signal Analyzer (VSA)
PurposeGenerates RF signals with specific characteristics for testing.Analyzes and demodulates RF signals to measure their properties.
FunctionalityUsed to create test signals for RF systems.Used to capture and analyze signals for troubleshooting and validation.
Input/OutputTakes digital/analog input to produce RF signals as output.Captures RF signals as input and provides analysis as output.
Key ComponentsModulators, synthesizers, DACs, and waveform memory.ADCs, mixers, filters, and digital signal processors (DSP).
Primary Use CasesDevice testing, calibration, and simulation of real-world conditions.Signal integrity testing, spectrum analysis, and demodulation.
Frequency RangeCovers a wide frequency range depending on the model.Also operates over a wide frequency range, typically matching VSG.
Output TypeRF signals with modulated and unmodulated options.Measurement data, including frequency, power, and modulation accuracy.
Software IntegrationOften includes signal creation software for custom waveforms.Comes with signal analysis software for detailed measurements.
Example ApplicationsTesting RF receivers, amplifiers, and transceivers.Debugging and verifying RF transmitter performance.
ComplexitySimpler in terms of operation; focused on signal generation.More complex due to signal analysis and diagnostic capabilities.
CostGenerally less expensive compared to VSA.Usually more expensive due to advanced analysis capabilities.

Article on RF Vector Signal Generation and Analysis

Refer our article on RF signal generation and analysis useful for testing wireless device compliant to IEEE or 3GPP standards viz. WLAN, WiMAX, LTE etc.

CompanyRF VSG modelRF VSA model
National Instruments- www.ni.com/NI RFSG Models available: PXI-5670, NI PXI-5671, NI PXIe-5672, NI PXIe-5673NI RFSA Models available: PXI-5660, PXI-5661
Agilent Technologies-www.home.agilent.com/N5182A MXG vector signal generator, M9381A PXIe Vector Signal GeneratorM9392A PXI Vector Signal Analyzer along woth VSA software(89600), Frequency- 50MHz to 26.5GHz
Rohde and Schwarz - www.rohde-schwarz.co.in/R&S ® SMU200A , R& S ® SMBV100AR&S ® FS-K96 OFDM Vector Signal Analysis, R& S ® CMW500
Anritsu - www.anritsu.com/MG3710A Vector Signal GeneratorMT8870A, MS2830A Signal Analyzer
Litepoint-www.litepoint.comIQview along with IQsignal ™ Signal Analysis Software Suite for WLAN VSG/VSA. IQflex ™ All in One for WLAN/bluetooth vector signal analysis

Conclusion

Both the RF Vector Signal Generator and Vector Signal Analyzer are essential in the development, testing and maintenance of RF systems. While the VSG excels in signal generation, the VSA provides invaluable insights through detailed signal analysis. By understanding their distinct functionalities and applications, RF professionals can effectively leverage these tools to ensure high performance and reliability in modern communication systems.