The Keysight N8974A (formerly Agilent) is a high-performance, 10 MHz to 6.7 GHz Noise Figure Analyzer from the NFA Series. Designed for fast, accurate, and repeatable noise figure and gain measurements, it features a dedicated second GPIB port for local oscillator (LO) control, six user-selectable measurement bandwidths, and compatibility with Smart Noise Sources (SNS) to simplify complex setups and deliver highly reliable results.

Specifications

General

ParameterValue
InterfacesGPIB (2 ports: System and dedicated LO control), LAN, RS-232, Centronics Parallel, VGA out
Display6.7-inch color LCD, 640 x 480 VGA resolution

Physical

ParameterValue
Power Supply90 to 260 V AC, 47 to 63 Hz, 150 VA maximum
Operating Temperature0 to 55 °C
Dimensions (W×H×D)426 mm W × 177 mm H × 437 mm D
Weight15.5 kg

Frequency Characteristics

ParameterValue
Frequency Range10 MHz to 6.7 GHz
Tuning Resolution1 Hz
Frequency Reference Aging Rate±1 x 10^-7 per year
Frequency Reference Temperature Stability±1 x 10^-6 (0 to 55 °C)
External Reference Input Frequency10 MHz (nominal)
External Reference Input Power Level-15 dBm to +10 dBm

Noise Figure & Gain Measurement Performance

ParameterValue
Noise Figure Measurement Range0 to 30 dB
Noise Figure Instrument Uncertainty (10 MHz to 3.0 GHz)±0.05 dB
Noise Figure Instrument Uncertainty (3.0 GHz to 6.7 GHz)±0.10 dB
Noise Figure Resolution0.01 dB
Gain Measurement Range-20 to +40 dB
Gain Instrument Uncertainty (10 MHz to 3.0 GHz)±0.17 dB
Gain Instrument Uncertainty (3.0 GHz to 6.7 GHz)±0.25 dB
Gain Resolution0.01 dB
Y-Factor Resolution0.01 dB

RF Input & Port Characteristics

ParameterValue
RF Input Connector TypeAPC 3.5 (m)
RF Input Impedance50 Ω nominal
RF Input VSWR (10 MHz to 3.0 GHz)< 1.5:1
RF Input VSWR (3.0 GHz to 6.7 GHz)< 1.8:1
Maximum Safe DC Input Voltage±20 Vdc
Maximum Safe RF Input Power+15 dBm continuous

Intermediate Frequency (IF) & Bandwidths

ParameterValue
Selected IF Bandwidths4 MHz, 2 MHz, 1 MHz, 400 kHz, 250 kHz, 100 kHz

Measurement & Sweep Capabilities

ParameterValue
Supported Device Types (DUT)Amplifier, Downconverter, Upconverter
Measurement ModesAmplifier, Downconverter (fixed/variable LO), Upconverter (fixed/variable LO)
Sweep Points Range2 to 401 points
Averaging Range1 to 1024 (user selectable)
User Calibration Types1-stage (Amplifier), 2-stage (Frequency Converter)
Local Oscillator (LO) ControlDedicated second GPIB port for external LO sweep synchronization

Noise Source Compatibility & Drive

ParameterValue
Noise Source Drive Voltage28 V ±0.1 V (pulsed)
Noise Source Drive PortBNC female (front panel)
Smart Noise Source (SNS) CompatibilityCompatible with Agilent/Keysight N4000A series SNS
ENR Table Storage CapacityUp to 30 tables internally

Display & User Interface

ParameterValue
Trace FormatsGraphic, Table, Meter
Number of Measurement Traces2 simultaneous traces
Marker Functions4 markers with normal and delta modes
Limit Line Testing CapabilitiesUpper and lower limit lines with pass/fail notification

System, Memory & I/O Interfaces

ParameterValue
Internal Data Storage Capacity3.5-inch floppy disk drive (1.44 MB) and internal non-volatile flash RAM
External Trigger Input PortBNC female
Remote Programming LanguageSCPI

Physical & Environmental Specifications

ParameterValue
Operating Humidity RangeUp to 95% RH at 40 °C (non-condensing)
Warm-up Time1 hour

Compliance & Certifications

ParameterValue
Recommended Calibration Cycle1 year
Standard Warranty1 year

Frequency Reference (Option 1D5)

ParameterValue
Option 1D5 Frequency Reference Aging Rate< ±1 × 10^-7 per year
Option 1D5 Frequency Reference Temperature Stability< ±1.5 × 10^-8

Rear Panel Connections

ParameterValue
Dedicated LO GPIB PortIEEE-488 interface dedicated to external local oscillator control
VGA Output Port15-pin D-sub, female
Serial Interface Port9-pin D-sub male, RS-232 compatible
Parallel Interface Port25-pin D-sub female, Centronics compatible

Storage & Media

ParameterValue
Floppy Disk Drive3.5-inch MS-DOS compatible, 1.44 MB

General & Environmental

ParameterValue
Maximum AC Power Consumption150 VA
Operating Altitude LimitUp to 3,000 meters (9,842 feet)
Storage Altitude LimitUp to 15,240 meters (50,000 feet)
Acoustic Noise Emission< 42 dBA (low fan speed), < 50 dBA (high fan speed)
Safety Compliance StandardsConforms to EN 61010-1 / IEC 1010-1, CSA C22.2 No. 1010.1
EMC Compliance StandardsConforms to EN 55011 / CISPR 11 Group 1 Class A

Performance

ParameterValue
Instrument Noise Figure (10 MHz to 3.0 GHz)< 10 dB
Instrument Noise Figure (3.0 GHz to 6.7 GHz)< 13 dB

Inputs & Outputs

ParameterValue
Rear Panel IF Output Frequency21.4 MHz
Rear Panel IF Output Impedance50 Ω (nominal)
Rear Panel 10 MHz Reference Output Power≥ 0 dBm (nominal)
Rear Panel 10 MHz Reference Output ConnectorBNC female
Trigger Output LevelTTL compatible, nominal 0 to 5 V
Smart Noise Source (SNS) Connector11-pin multi-port

Power

ParameterValue
AC Input Voltage Range90 to 250 V AC
AC Power Line Frequency50 to 60 Hz (at 90 to 250 V AC), 400 Hz (at 90 to 132 V AC)

Technology

Noise Figure Analysis

Applications

Amplifier and frequency translating device characterization