Product Introduction
The NI PXIe-5668 is a high-performance PXI Express vector signal analyzer (VSA) designed for demanding RF and microwave measurement applications including wireless communications testing, RFIC characterization, radar validation, spectrum monitoring, signal intelligence, and high-volume automated manufacturing test.
Depending on the selected configuration, the PXIe-5668 provides RF frequency coverage up to 14 GHz or 26.5 GHz and instantaneous analysis bandwidth configurations ranging from 80 MHz to as high as 765 MHz. This combination of wide frequency coverage, large analysis bandwidth, high dynamic range, and PXI measurement speed makes the PXIe-5668 suitable for both advanced R&D and automated production environments.
The PXIe-5668 uses a modular architecture combining the PXIe-5606 RF downconverter, PXIe-5624 IF digitizer, and PXIe-5653 RF analog signal generator. An optional PXIe-5698 preamplifier can also be added to improve sensitivity and dynamic range when measuring low-level RF signals.
Product Overview
The National Instruments PXIe-5668 is an FFT-based spectrum and vector signal analyzer that combines wide instantaneous bandwidth with high microwave measurement performance.
Its architecture is optimized for applications requiring low phase noise, low noise floor, excellent linearity, wide dynamic range, and rapid signal acquisition. Typical measurements include error vector magnitude (EVM), adjacent channel power (ACP), adjacent channel leakage ratio (ACLR), intermodulation distortion (IMD), harmonic measurements, occupied bandwidth, spectrum masks, radar pulse analysis, and wideband spectral monitoring.
As a PXI Express instrument, the PXIe-5668 can also be synchronized with other PXI instruments for phase-coherent MIMO measurements and complex automated RF test systems.
Key Features
Frequency Coverage up to 26.5 GHz
The PXIe-5668 is available in multiple RF frequency configurations for microwave signal analysis.
- 20 Hz to 14 GHz configurations
- 20 Hz to 26.5 GHz configurations
- RF and microwave signal analysis
- Wireless communication testing
- Radar and aerospace measurements
- RFIC characterization
Advantage: Frequency coverage extending to 26.5 GHz allows one PXI instrument to address a wide range of RF and microwave applications without requiring separate analyzers for lower and higher frequency bands.
Up to 765 MHz Instantaneous Bandwidth
The PXIe-5668 provides extremely wide instantaneous analysis bandwidth for wideband RF measurements.
- 80 MHz bandwidth configurations
- 200 MHz bandwidth configurations
- Up to 765 MHz instantaneous bandwidth configurations
- Wideband vector signal analysis
- Radar pulse acquisition
- Wideband spectrum monitoring
Advantage: A large instantaneous bandwidth allows wide signals and spectrum masks to be captured in a single acquisition, reducing measurement time and avoiding frequency stitching.
Wideband Signal Analysis
The PXIe-5668 is designed for broadband modulation and spectrum measurements where the complete signal must be analyzed simultaneously.
- Wideband EVM measurements
- Spectrum mask testing
- Broadband modulation analysis
- Radar pulse characterization
- Wideband RF recording
Advantage: Wide instantaneous bandwidth is particularly valuable when testing modern communication standards and radar signals with large occupied bandwidths.
High Dynamic Range
The PXIe-5668 combines low noise and excellent linearity to provide high dynamic range for demanding spectrum measurements.
- Low average noise level
- High third-order intercept performance
- Excellent spurious-free dynamic range
- Strong adjacent-channel measurement capability
- Low-level signal detection
Advantage: High dynamic range allows the analyzer to measure very small signals in the presence of significantly larger carriers and interferers.
Average Noise Level as Low as Approximately -166 dBm/Hz
NI specifies an average noise level of approximately -166 dBm/Hz between 300 MHz and 1.7 GHz for standard PXIe-5668 configurations.
- Low instrument noise floor
- Sensitive RF measurements
- Low-level signal detection
- Spectrum monitoring
- RF characterization
Advantage: Low noise performance improves the ability to characterize low-power signals and spurious emissions.
Third-Order Intercept up to Approximately +25 dBm
The PXIe-5668 provides strong linearity performance with typical third-order intercept performance around +25 dBm.
- High linearity
- Intermodulation measurements
- Adjacent channel measurements
- RF amplifier characterization
- RFIC validation
Advantage: Strong TOI performance improves accuracy when measuring intermodulation products and signals near high-power carriers.
2 GB Onboard Memory
PXIe-5668 configurations provide 2 GB of onboard acquisition memory.
- 2 GB onboard memory
- Long waveform acquisition
- Wideband signal recording
- Radar pulse capture
- RF transient analysis
Advantage: Large onboard memory supports longer acquisitions at high sampling rates.
2 GS/s IF Digitizer Architecture
The PXIe-5668 incorporates the PXIe-5624 high-speed IF digitizer, enabling extremely wideband signal acquisition.
- 2 GS/s digitizer architecture
- Wideband IF acquisition
- Digital downconversion
- I/Q signal generation from acquired IF data
- High-speed FFT spectrum analysis
Advantage: The high-speed digitizer enables both wide instantaneous bandwidth and flexible vector signal analysis.
Low-Band and High-Band RF Architecture
The PXIe-5668 uses separate RF architectures optimized for different frequency regions.
- Three-stage superheterodyne architecture below 3.6 GHz
- Two-stage architecture above 3.6 GHz
- YIG-tuned preselector for microwave measurements
- Optimized low-band sensitivity
- Optimized high-band dynamic range
Advantage: Separate RF paths allow NI to optimize both lower-frequency measurement performance and high-frequency microwave analysis.
YIG-Tuned Preselector
For high-frequency measurements above approximately 3.6 GHz, the PXIe-5668 uses a YIG-tuned filter as an RF preselector.
- Microwave preselection
- Improved image rejection
- Reduced out-of-band interference
- High-frequency spectrum analysis
Advantage: RF preselection improves measurement performance when strong signals exist outside the analyzed frequency band.
Optional PXIe-5698 Preamplifier
The optional PXIe-5698 preamplifier can be integrated with the PXIe-5668 to improve low-level signal measurement performance.
- Improved sensitivity
- Lower effective noise floor
- Low-power RF signal measurements
- Enhanced dynamic range near the instrument noise floor
Advantage: The optional preamplifier is useful when detecting and characterizing extremely low-power RF signals.
PXI Multi-Instrument Synchronization
The modular PXI Express architecture allows the PXIe-5668 to be synchronized with other RF and measurement instruments.
- Multi-instrument synchronization
- Phase-coherent measurements
- MIMO test systems
- Parallel RF measurements
- Automated test integration
Advantage: Multiple analyzers can be coordinated for phase-coherent multi-channel RF applications.
High-Speed Automated Test
The PXIe-5668 is designed not only for R&D measurements but also for high-volume automated RF production testing.
- Fast measurement execution
- High-throughput production testing
- Automated RF validation
- Parallel PXI test architectures
- RF semiconductor manufacturing
Technical Specifications
| Parameter | Description |
|---|---|
| Product Type | PXI Vector Signal Analyzer / Spectrum Analyzer |
| Model | NI PXIe-5668 |
| Frequency Range Options | 20 Hz to 14 GHz / 20 Hz to 26.5 GHz |
| Maximum Frequency | 26.5 GHz |
| Instantaneous Bandwidth Options | 80 MHz / 200 MHz / Up to 765 MHz |
| Maximum Instantaneous Bandwidth | 765 MHz |
| Average Noise Level | Approximately -166 dBm/Hz from 300 MHz to 1.7 GHz |
| Third-Order Intercept | Approximately +25 dBm Typical |
| Onboard Memory | 2 GB |
| IF Digitizer | PXIe-5624 |
| RF Downconverter | PXIe-5606 |
| RF Local Oscillator | PXIe-5653 |
| Optional Preamplifier | PXIe-5698 |
| Digitizer Sample Rate | 2 GS/s Architecture |
| High-Band Preselector | YIG-Tuned Filter |
| Bus Interface | PXI Express |
| Primary Applications | Wireless Communications, RFIC Characterization, Radar Test, Spectrum Monitoring and Signal Intelligence |
PXIe-5668 Configurations and Part Numbers
| Part Number | Frequency Range | Bandwidth Configuration |
|---|---|---|
| 783156-01 | 20 Hz to 14 GHz | 80 MHz |
| 783156-02 | 20 Hz to 14 GHz | 200 MHz |
| 783156-03 | 20 Hz to 14 GHz | Wideband Configuration / Up to 765 MHz |
| 783124-01 | 20 Hz to 26.5 GHz | 80 MHz |
| 783124-02 | 20 Hz to 26.5 GHz | 200 MHz |
| 783124-03 | 20 Hz to 26.5 GHz | Wideband Configuration / Up to 765 MHz |
The exact frequency range and instantaneous bandwidth depend on the selected PXIe-5668 part number. Buyers should verify the complete part number before ordering a replacement or expanding an existing RF test system.
RF Measurement Capabilities
The PXIe-5668 supports a broad range of spectrum and vector signal measurements.
- Channel power
- Adjacent channel power
- ACLR measurements
- Error vector magnitude
- Occupied bandwidth
- Spectrum emission masks
- Intermodulation distortion
- Harmonic analysis
- Spurious measurements
- Radar pulse analysis
Software Ecosystem
The NI PXIe-5668 integrates with NI RF software for spectrum analysis, modulation measurements, automated testing, and wireless standards validation.
- NI-RFSA: Provides low-level control of the vector signal analyzer for RF acquisition, frequency configuration, reference-level control, and I/Q data acquisition.
- RFmx: Provides optimized personality-based RF measurements for spectrum analysis, wireless standards testing, and automated RF validation.
- LabVIEW: Enables development of customized RF measurement, automation, visualization, and signal-processing applications.
- TestStand: Allows PXIe-5668 measurements to be incorporated into automated production and validation sequences.
Industries
- Wireless Communications
- Semiconductor Testing
- RFIC Development
- Aerospace and Defense
- Radar Development
- Spectrum Monitoring
- Signal Intelligence
- Electronic Manufacturing
- Research Laboratories
Applications
Wireless Communications Testing
The PXIe-5668 can perform wideband vector signal measurements for wireless communication devices and systems.
- EVM measurements
- Channel power
- ACLR testing
- Spectrum masks
- Modulation analysis
RFIC Characterization
High dynamic range and wide frequency coverage make the PXIe-5668 suitable for RF semiconductor characterization.
- RF amplifier testing
- Mixer characterization
- Intermodulation testing
- Noise and spurious measurements
- RF front-end validation
Radar Testing
Wide instantaneous bandwidth enables the PXIe-5668 to analyze short-duration and broadband radar signals.
- Radar pulse analysis
- Wideband waveform acquisition
- Frequency and phase measurements
- Pulse characterization
- Radar transmitter validation
Spectrum Monitoring
The PXIe-5668 provides wideband spectrum acquisition for monitoring and signal-detection applications.
- Wideband spectrum monitoring
- Signal detection
- Interference analysis
- Spurious signal identification
- RF environment characterization
Signal Intelligence Research
High bandwidth, microwave frequency coverage, and low noise performance make the PXIe-5668 suitable for advanced signal-intelligence research applications.
- Wideband RF capture
- Unknown signal analysis
- Signal classification research
- Spectrum surveillance research
High-Volume Manufacturing Test
The PXI Express architecture is optimized for automated test throughput.
- RF semiconductor production testing
- Wireless device manufacturing
- Automated RF validation
- Parallel test architectures
- High-speed measurement sequences
Comparison with Similar PXI RF Instruments
| Model | Main Difference | Best Application |
|---|---|---|
| NI PXIe-5668 | High-performance vector signal analyzer with configurations up to 26.5 GHz and up to 765 MHz instantaneous bandwidth. | Microwave RF analysis, radar and wideband signal testing |
| NI PXI-5661 | Earlier-generation PXI vector signal analyzer with lower frequency and bandwidth capability. | General RF spectrum and vector signal measurements |
| NI PXIe-5663E | Mid-range PXI vector signal analyzer for RF communications and automated testing applications. | General-purpose wireless and RF testing |
| NI PXIe-5841 | Newer vector signal transceiver integrating both RF generation and analysis with wider reconfigurable test capabilities. | Modern RF semiconductor and wireless validation |
Recommended Related Products
| NI PXIe-5698 | RF preamplifier designed to improve PXIe-5668 sensitivity and dynamic range near the analyzer noise floor. |
| NI PXIe-5841 | Vector signal transceiver for applications requiring integrated RF generation and analysis in a newer PXI platform. |
| NI PXIe-5663E | PXI vector signal analyzer for general RF and wireless communications measurements. |
Why Choose PXIe-5668?
- Frequency coverage up to 26.5 GHz
- 14 GHz and 26.5 GHz configurations available
- Instantaneous bandwidth up to 765 MHz
- 80 MHz and 200 MHz configurations also available
- Excellent RF dynamic range
- Average noise level approximately -166 dBm/Hz in key frequency ranges
- Third-order intercept around +25 dBm typical
- 2 GB onboard memory
- 2 GS/s IF digitizer architecture
- YIG-tuned microwave preselector
- Optional PXIe-5698 preamplifier
- PXI multi-instrument synchronization
- Suitable for phase-coherent MIMO testing
- Optimized for RF R&D and production test
- Ideal for radar and spectrum monitoring applications
Frequently Asked Questions
What is the NI PXIe-5668?
The NI PXIe-5668 is a high-performance PXI Express vector signal analyzer designed for spectrum analysis, vector signal analysis, wireless communications testing, RFIC characterization, radar measurement, spectrum monitoring, and signal intelligence applications.
What is the maximum frequency of the PXIe-5668?
The PXIe-5668 is available in configurations with maximum frequencies of 14 GHz or 26.5 GHz. The exact frequency range depends on the selected part number.
What is the maximum instantaneous bandwidth of the PXIe-5668?
Selected PXIe-5668 configurations provide instantaneous analysis bandwidth up to approximately 765 MHz. Other configurations are available with 80 MHz or 200 MHz bandwidth.
What are the PXIe-5668 part numbers?
NI lists six primary PXIe-5668 configurations: 783156-01, 783156-02, and 783156-03 for 14 GHz configurations, and 783124-01, 783124-02, and 783124-03 for 26.5 GHz configurations.
Does the PXIe-5668 have onboard memory?
Yes. NI specifies 2 GB of onboard acquisition memory for PXIe-5668 configurations.
Can the PXIe-5668 be used as a spectrum analyzer?
Yes. The PXIe-5668 is an FFT-based analyzer that supports high-performance spectrum analysis as well as vector signal analysis.
Can the PXIe-5668 measure modulated wireless signals?
Yes. The PXIe-5668 can perform vector signal measurements such as EVM, ACP, ACLR, spectrum masks, occupied bandwidth, and other modulation-related measurements when used with compatible NI RF software.
Can the PXIe-5668 be used for radar testing?
Yes. Radar testing is one of the key applications identified by NI. Its wide instantaneous bandwidth makes it particularly useful for radar pulse acquisition, wideband waveform analysis, and transmitter characterization.
Can the PXIe-5668 be used for RFIC testing?
Yes. Its wide frequency range, excellent dynamic range, high linearity, and fast PXI measurement architecture make the PXIe-5668 suitable for RFIC characterization and semiconductor production testing.
Does the PXIe-5668 support MIMO testing?
Yes. Multiple PXI instruments can be synchronized for phase-coherent measurements, making the PXIe-5668 suitable for multi-channel and MIMO RF test configurations.
What does the optional PXIe-5698 do?
The PXIe-5698 is an optional preamplifier that can improve measurement sensitivity and dynamic range when analyzing signals near the PXIe-5668 instrument noise floor.
What is the difference between the 14 GHz and 26.5 GHz PXIe-5668?
The primary difference is maximum RF frequency. Part numbers beginning with 783156 provide frequency coverage up to 14 GHz, while the 783124 configurations extend measurement capability to 26.5 GHz. Bandwidth configuration must also be verified separately.
What software supports the PXIe-5668?
The PXIe-5668 is supported by NI-RFSA and compatible NI RFmx software packages. It can also be integrated with LabVIEW and TestStand for customized RF measurement and automated test applications.
Is the PXIe-5668 still available from NI?
NI currently classifies the PXIe-5668 as a Mature product. This means it remains supported and may still be available, but NI no longer recommends it for new system designs. Availability and lead time depend on the selected part number.
Conclusion
The NI PXIe-5668 Vector Signal Analyzer is a high-performance PXI RF and microwave measurement platform for wireless communications, RFIC characterization, radar testing, spectrum monitoring, signal intelligence, and high-throughput production test. With configurations extending to 26.5 GHz, instantaneous bandwidth up to 765 MHz, high dynamic range, 2 GB onboard memory, a 2 GS/s IF digitizer architecture, optional low-noise preamplification, and PXI multi-instrument synchronization, the PXIe-5668 provides the performance required for demanding wideband RF measurement applications.
