The Keysight N9938A FieldFox is a rugged, handheld microwave spectrum analyzer operating from 5 kHz up to 26.5 GHz. Designed for tough field environments, it provides ±0.5 dB amplitude accuracy at power-up with no warm-up required, and is compliant with MIL-PRF-28800F Class 2 standards.
Specifications
General
| Parameter | Value |
|---|---|
| Interfaces | LAN, USB 2.0 Host (2 ports), USB 2.0 Device (Mini-B), SD Card slot |
| Display | 6.5-inch color transflective VGA LCD (640 × 480) |
| Storage Capacity | Internal memory (~4 GB), supports external SD card and USB flash drives |
| Warm-up Time | 5 minutes |
Physical
| Parameter | Value |
|---|---|
| Power Supply | 100 to 240 VAC, 50 to 60 Hz (via external AC/DC adapter); 15 VDC external input |
| Operating Temperature | -10 to 55 °C |
| Dimensions (W×H×D) | 188 mm × 292 mm × 72 mm |
| Weight | 3.0 kg |
Frequency
| Parameter | Value |
|---|---|
| Frequency Range | 100 kHz to 26.5 GHz (usable to 5 kHz; tunable to 0 Hz or DC) |
| Frequency Span Range | 0 Hz (zero span), 10 Hz to 26.5 GHz |
| Frequency Resolution | 1 Hz |
| Phase Noise at 10 kHz Offset | -111 dBc/Hz |
| Frequency Reference Aging Rate | ±1.0 ppm/year |
| Frequency Reference Temperature Stability | ±0.5 ppm (-10 to 55 °C) |
| Frequency Reference GPS Accuracy | ±0.010 ppm (with Option 307 GPS lock) |
Bandwidth
| Parameter | Value |
|---|---|
| Resolution Bandwidth (RBW) Range | 10 Hz to 5 MHz (-3 dB bandwidth) |
| RBW Steps | 1, 1.5, 2, 3, 5, 7.5, 10 sequence (Non-zero span) |
| Video Bandwidth (VBW) Range | 1 Hz to 5 MHz (1-3-10 sequence) |
Amplitude
| Parameter | Value |
|---|---|
| Absolute Amplitude Accuracy | ±0.5 dB (at power-up, no warm-up required) |
| Input Attenuator Range | 0 to 30 dB, in 5 dB steps |
| Maximum Safe Input Level (AC) | +27 dBm (0.5 W) average CW power |
| Maximum Safe Input Level (DC) | ±50 VDC |
| DANL (Preamp Off) 2 MHz to 4.5 GHz | -137 dBm |
| DANL (Preamp Off) >4.5 to 7 GHz | -133 dBm |
| DANL (Preamp Off) >7 to 13 GHz | -129 dBm |
| DANL (Preamp Off) >13 to 17 GHz | -124 dBm |
| DANL (Preamp Off) >17 to 22 GHz | -119 dBm |
| DANL (Preamp Off) >22 to 25 GHz | -114 dBm |
| DANL (Preamp Off) >22 to 26.5 GHz | DANL (Preamp Off) >25 to 26.5 GHz = -110 dBm |
| Spur-Free Dynamic Range | >=105 dB (nominal at 2.4 GHz) |
| Display Range (Log scale) | 10 divisions, 0.01 to 100 dB/division in 0.01 dB steps |
| Amplitude Scale Units | dBm, dBmV, dBµV, W, V, A, dBmA, dBµA |
| Trace Detectors | Normal, positive peak, negative peak, sample, average (RMS) |
| Trace States | Clear/write, max hold, min hold, average, view, blank |
| Number of Traces | 4 |
| Number of Averages | 1 to 10,000 |
Sweep and Trigger
| Parameter | Value |
|---|---|
| Sweep Acquisition Range (Span > 0 Hz) | Sweep Acquisition Range (Span = 0 Hz) = 1 to 5000 (number of data acquisitions per measurement) |
| Sweep Acquisition Resolution | 1 |
Inputs and Outputs
| Parameter | Value |
|---|---|
| RF Input VSWR (10 MHz to 2.7 GHz) | 1.7 : 1 (nominal, 10 dB attenuation) |
| RF Input VSWR (>2.7 to 7.5 GHz) | 1.5 : 1 (nominal, 10 dB attenuation) |
| RF Input VSWR (>7.5 GHz) | 2.2 : 1 (nominal, 10 dB attenuation) |
Measurement Modes and Suites
| Parameter | Value |
|---|---|
| Standard Measurement Functions | Channel power, occupied bandwidth, adjacent channel power ratio |
| Built-in Power Meter Range | 9 kHz to 26.5 GHz |
Physical and Power
| Parameter | Value |
|---|---|
| Battery Life | 4 hours |
| Enclosure Durability | Completely sealed, compliant with U.S. MIL-PRF-28800F Class 2 |
| Form Factor | Vertical (portrait) orientation with large buttons (glove friendly) |
Inputs & Outputs
| Parameter | Value |
|---|---|
| RF Input Connector | 3.5 mm female, 50 Ω nominal |
| External Reference Input | BNC female, 10 MHz |
Environmental & Durability
| Parameter | Value |
|---|---|
| IP Rating | IP53 (dust and water resistant) |
| Military Compliance | MIL-PRF-28800F Class 2 |
| Maximum Operating Altitude | 4,572 m (15,000 ft) |
| Storage Temperature | -51 to +71 °C (without battery) |
Preamplifier
| Parameter | Value |
|---|---|
| Preamplifier Option Frequency Range | 100 kHz to 26.5 GHz (Option 235) |
| Preamplifier Nominal Gain | 20 dB (Option 235) |
Real-Time Spectrum Analyzer
| Parameter | Value |
|---|---|
| Real-Time Spectrum Analyzer (RTSA) Bandwidth | 10 MHz (Option 350) |
| Minimum Signal Duration for 100% POI | 122 us (Option 350, 10 MHz Span, RBW 300 kHz) |
Tracking Generator
| Parameter | Value |
|---|---|
| Tracking Generator Frequency Range | 30 kHz to 26.5 GHz (Option 210) |
| Tracking Generator Output Power Range | -15 dBm to -45 dBm (Option 210, 1 dB steps) |
Triggering
| Parameter | Value |
|---|---|
| Trigger Sources | Free run, External, Video, RF Burst |
Performance
| Parameter | Value |
|---|---|
| Third-Order Intercept (TOI) | +15 dBm (typical, at 2.4 GHz) |
Environmental
| Parameter | Value |
|---|---|
| Operating Humidity Range | Up to 95% relative humidity at 40 °C (non-condensing) |
Technology
RF and Microwave Spectrum Analysis
Applications
Field testing, transmitter power measurement, cable and antenna analysis, interference hunting