The Keysight (formerly Agilent) E4991A is an RF impedance and material analyzer designed to deliver high-precision component and material evaluation from 1 MHz to 3 GHz. It features a basic impedance measurement accuracy of ±0.8% and provides a comprehensive set of sweep parameters including frequency, AC signal level, and DC bias. Operating on a Windows-based architecture, the analyzer includes built-in VBA programming capabilities for streamlined automation. With available options, the E4991A can perform direct read-outs of material permittivity and permeability, as well as complex on-wafer and temperature characteristic measurements.

Specifications

General

ParameterValue
InterfacesLAN, GPIB
DisplayColor LCD with Windows-styled user interface
Internal StorageInternal HDD and 3.5-inch 1.44 MB Floppy Disk Drive
Warm-up Time30 minutes

Physical

ParameterValue
Power Supply90 to 132 VAC / 198 to 264 VAC, 47 to 63 Hz, 350 VA max
Operating Temperature5 to 40 °C

Test Signal Characteristics

ParameterValue
Frequency Range1 MHz to 3 GHz

Measurement Parameters

ParameterValue
Impedance Parameters|Z|, |Y|, θ, R, X, G, B, L, C, D, Q, |Γ|, Γx, Γy
Material Measurement ParametersPermittivity (ε), Permeability (μ) (Option dependent)

Measurement Range and Accuracy

ParameterValue
Basic Impedance Accuracy±0.8%

Sweep Characteristics

ParameterValue
Sweep ParametersFrequency, AC Level, DC Bias
Number of Sweep Points2 to 801 points

Display and Analysis

ParameterValue
Programming / ScriptingBuilt-in VBA (Visual Basic for Applications) programming function

Material Measurement (Optional)

ParameterValue
Material MeasurementDirect read-out permittivity and permeability (Option dependent)

General Specifications

ParameterValue
On-Wafer MeasurementSupported (Option dependent)
Temperature Characteristic MeasurementSupported (Option dependent)
Test Fixture CompatibilitySupports various test fixtures for components

Inputs & Outputs

ParameterValue
Test Port Connector7 mm (APC-7) on test head
Output Impedance50 Ω (nominal)

Performance

ParameterValue
DC Bias (Option 001)±40 V, ±50 mA

Calibration & Correction

ParameterValue
Calibration MethodsOpen, Short, Load, Low-Loss Capacitor
Compensation MethodsOpen, Short, Port Extension, Fixture Electrical Length

Frequency

ParameterValue
Frequency Resolution1 mHz

Measurement

ParameterValue
Impedance Measurement Range120 mΩ to 52 kΩ (10% accuracy range)
Averaging1 to 999 factor

Control & Trigger

ParameterValue
Trigger ModesInternal, External, Manual, Bus

Technology

RF Impedance and Material Analysis

Applications

High-frequency component evaluation, dielectric and magnetic material characterization, on-wafer testing