The Keysight FieldFox B series combines cable & antenna tester (CAT), vector network analyzer (VNA) and spectrum analyzer (SA) in one robust, battery-operated handheld device. The analyzers are designed for field use: shockproof, dustproof and splashproof, with a large display that is easy to read in sunlight, large buttons (can also be operated with gloves) and a field-swappable battery for several hours of measurement operation. Thanks to CalReady, the device is ready to measure as soon as it is switched on; optional ECal modules speed up precise calibrations. Software options such as Real-Time Spectrum Analysis (RTSA) up to 120 MHz, IQ Analyzer/Streaming, Noise Figure, Pulse Measurements, EMF/EMI and OTA Measurements (LTE/5G NR) are available for demanding applications. Typical applications include installation, troubleshooting and maintenance of cellular, SAT, radar, broadcast, WLAN and industrial RF systems - from cable termination to filters/amplifiers to over-the-air analysis.
The N9951B belongs to the N995xB series within the FieldFox-B family and is a portable spectrum analyzer with an extended frequency range from 9 kHz to 44 GHz. It is aimed at users who need to analyze high-frequency signals in the Ka band and beyond - for example in satcom, radar, 5G mmWave, defence and research systems. Compared to the N9950B (up to 32 GHz), the N9951B offers a wider bandwidth and enables precise characterization of signals in the upper Ka-band. It combines the highest frequency coverage with the proven robustness and operating philosophy of the FieldFox series. Like all models in the N995xB range, the N9951B is fully software upgradeable and supports the same analysis options - from RTSA and IQ streaming to pulse and EMC measurements. This makes it the preferred choice for mobile RF measurements that require the highest accuracy and range.
Technical product features of the series:
- Meter combination: CAT, VNA and/or SA depending on model; the N9951B is a specialized spectrum analyzer with optional functions for RTSA and IQ analysis.
- Frequency ranges depending on model: from 30 kHz to 54 GHz (N9950B to N9962B); the N9951B covers up to 44 GHz.
- Ruggedized design: for field use (-10 ... +55 °C), shock/vibration-resistant; dust and splash-proof design according to MIL standard.
- Mobile & ergonomic: approx. 3.3 kg, large transflective display, large buttons, glove-operated, replaceable battery (up to 4.5 h runtime).
- High measurement accuracy: Stable frequency oscillator (±0.9 ppm), optional GPS reference, automatic calibration; excellent amplitude accuracy over the entire frequency range.
- Flexible analysis: Options for RTSA (up to 120 MHz real-time BW), IQ acquisition/streaming, noise figure, pulse and EMC measurements, OTA (LTE/5G), channel scanner, interference/spectral monitoring.
- Dynamics & sensitivity: Typically up to 112 dB dynamic range, with preamplifier up to 100 dB below 2 MHz and 112 dB up to 7 GHz; high linearity and low self-noise level.
- Interfaces & GPS: USB & LAN, external Ref/Trigger, optional integrated GNSS, support for external USB power sensors and built-in power meter (option).
- Software ecosystem: Connection to PathWave 89600 VSA, Keysight Surveyor/Spectrum Management and others. etc.; remote control via SCPI.
- Accessories & upgrades: numerous field upgrades via license key (RTSA, pulse analysis, EVM, noise figure, OTA, EMI analyzer, tracking generator and much more).
