The Keysight N9918B FieldFox is a portable handheld microwave analyzer integrating multiple instrument functions into a single 3.34 kg unit for field RF and microwave measurements. Operating from 9 kHz to 26.5 GHz, it delivers cable and antenna analysis, vector network analysis, and spectrum analysis capabilities with up to 115 dB system dynamic range. The instrument features a 6.5-inch transflective color LCD display, over 5 hours battery life, and operates across -10 to +55 °C. Built-in dual ports support Distance-to-Fault measurements, return loss analysis, and cable loss characterization with CalReady, OSL, and response calibrations. Optional modules enable real-time spectrum analysis up to 100 MHz gap-free bandwidth, 5G NR and LTE over-the-air measurements, GPS/GNSS geolocation, and external power sensor integration. Spectrum analyzer measurements achieve ±0.3 dB accuracy without warm-up, with DANL performance up to 15 dB better and phase noise 10 dB superior to previous FieldFox generations.
Technical Specifications
• Frequency Range: 9 kHz to 26.5 GHz (Spectrum Analyzer); 30 kHz to 26.5 GHz (CAT/VNA)
• Analysis Bandwidth: 10 MHz standard; 40 MHz (Option B04), 100 MHz (Option B10) optional
• Ports: 2 built-in
• VNA System Dynamic Range: >114 dB
• Display: 6.5-inch transflective color LCD-LED
• Weight: 3.34 kg (7.35 lb)
• Dimensions: 11.5 × 7.4 × 3.2 inches
• Operating Temperature: -10 to +55 °C
• Battery Life: Over 5 hours
• Spectrum Analyzer Accuracy: ±0.3 dB (without warm-up)
– Key Features
• Cable and Antenna Analyzer with Distance-to-Fault, return loss, and cable loss measurements
• Vector Network Analyzer measuring all four S-parameters simultaneously
• Spectrum Analyzer with ±0.3 dB accuracy and improved DANL performance
• Real-Time Spectrum Analysis up to 100 MHz gap-free bandwidth for intermittent signal capture
• Over-the-air measurements for 5G NR, LTE FDD/TDD, and 5GTF
• Optional GPS/GNSS receiver (Option 307) for geolocation and timestamping
• Optional built-in power meter (Option 310) and external USB power sensor support (Option 302)
• Phase measurements available with Option 210
– Typical Applications
• 5G deployment and validation
• Satellite communications testing
• Signal monitoring and analysis
• Electronic warfare measurements
• Field maintenance and troubleshooting
• Network performance validation
– Compatibility & Integration
GPS antenna N9910X-825 compatible with Option 307. Supports optional vector voltmeter functionality and external USB power sensor integration.
















