Agilent/Keysight N9950B

The Keysight N9950B FieldFox is a handheld microwave analyzer delivering benchtop-grade RF and microwave measurement capability in a field-deployable package. It combines cable and antenna testing, vector network analysis, spectrum analysis, and real-time signal capture in a single instrument, enabling rapid troubleshooting and characterization across frequency ranges from 9 kHz to 32 GHz.

Technical Specifications

Frequency Coverage

• Cable and Antenna Analyzer (CAT): 300 kHz to 32 GHz


• Vector Network Analysis: 300 kHz to 32 GHz


• Spectrum Analysis: 9 kHz to 32 GHz


• Analysis bandwidth: Up to 120 MHz


• Real-time bandwidth: 120 MHz gap-free System Performance


• Dynamic range: 105 dB


• Spectrum analyzer amplitude accuracy: ±0.2 dB (no warm-up required)


• Frequency reference: ±0.9 ppm (spec), ±0.5 ppm (typical) at –10 to 55 °C; ±0.010 ppm when GPS-locked


• Frequency aging: ±1 ppm/yr over 20 years


• System impedance: 50 Ω nominal (75 Ω with adapter and calibration)


• Real-time signal capture: 5.52 µs minimum signal duration at 100% Probability of Intercept IF Bandwidth Options

3 Hz, 10 Hz, 30 Hz, 100 Hz, 300 Hz, 1 kHz, 3 kHz, 10 kHz, 30 kHz, 100 kHz (VNA mode)

Key Features

• Cable and Antenna Analyzer with DTF, return loss, and 1-port cable loss measurements


• Vector Network Analyzer: 2-port S-parameters (S11, S21, S12, S22) with magnitude and phase; mixed-mode measurements (Scc11, Sdd11, Scd11, Sdc11)


• Real-Time Spectrum Analyzer with 120 MHz gap-free capture


• Time Domain Reflectometry (TDR) for cable fault location


• Pulse measurements and RF characterization


• Power meter functionality via USB sensor integration


• AM/FM analog demodulation


• Noise figure measurements


• Frequency counter, vector voltmeter, and interference analyzer


• Built-in GPS receiver for geolocation and time stamping


• Over-the-air (OTA) measurements for 5G NR and LTE


• ECal support and multiple calibration methods (OSL, response, CalReady)

Typical Applications

• Field verification of passive and active RF/microwave components


• Cable and connector diagnostics


• Network performance validation and fault isolation


• 5G and cellular field testing


• EMI/RFI identification and characterization


• Antenna pattern and impedance measurement in deployed environments

Compatibility & Integration Supports USB power sensors for extended measurement capability. GPS locking available for improved frequency reference stability in field operations.