The Keysight (Agilent/HP) N4431B is an RF electronic calibration (ECal) module for vector network analyzers (VNAs). It provides a single-connection electronic calibration technique that performs full three- or four-port calibrations faster than mechanical cal kits while preserving comparable accuracy.

Specifications

General

ParameterValue
InterfacesUSB (direct control by Keysight PNA and ENA series VNAs)
DisplayNone (no local user display)

Identification

ParameterValue
ManufacturerKeysight Technologies (formerly Agilent/HP)
Model Number / Part NumberN4431B
SeriesECal module series
Product NameRF electronic calibration (ECal) module
Manufacturer legacy noteOriginally marketed under Agilent/HP; now Keysight Technologies

Overview

ParameterValue
Intended useProvide fast, single-connection electronic calibration for vector network analyzers; transfer-calibration standard
Supported measurements / calibration scopeFull three- or four-port calibrations (single-connection ECal)
Key featuresSingle-connection ECal, fast 3- or 4-port calibration, solid-state switching, NIST-traceable accuracy, USB control
Typical applicationsVNA calibration and verification; laboratory and production VNA setups where reduced calibration time and connector wear are desired
Switching technologyReliable solid-state switching (no mechanical switching required for internal standards)
Typical workflowConnect the single ECal module to the VNA test port and perform automated calibration via VNA control software
Recommended use caseLaboratory and production environments requiring frequent calibrations and reduced downtime
Benefit vs mechanical cal kitsFewer operator connections and less operator interaction reduces human error during calibration

Electrical / RF Performance - General

ParameterValue
Frequency range (overall)9 kHz to 13.5 GHz

Calibration Functions and Standards

ParameterValue
Transfer-standard capabilityECal module serves as a transfer standard capable of transferring factory calibration accuracy to the network analyzer
TraceabilityNIST-traceable accurate calibrations
Factory data / factory calibrationFactory calibration data / transfer-standard calibration supplied (module is a transfer standard)
Included / provided calibration capabilityProvides the internal standards required to perform VNA automated calibration sequences (single-connection ECal)

Control, Interfaces and Communication

ParameterValue
Control interface detailsUSB interface for direct control by Keysight PNA and ENA series VNAs
VNA compatibility notesDirectly controlled by Keysight PNA and ENA series network analyzers
Notes on controlControlled by the VNA over USB; the VNA software automates the ECal sequence (operator only connects module)

Mechanical & Physical

ParameterValue
Connector arrangement (external)Four RF test ports (one per VNA port); user connects each VNA port to a corresponding ECal port
Nominal impedance50 ohm
Effect on connector wearReduces connector wear versus repeated mechanical calibrations (single external connection)

Technology

Electronic calibration (ECal) module for VNAs

Applications

Calibration of vector network analyzers (PNA and ENA series); transfer-standard VNA calibrations