Agilent/Keysight N1021B

The Agilent/Keysight N1021B is an 18 GHz differential TDR/TDT probe kit engineered for high-speed signal integrity characterization on PCBs and components lacking standard RF connectors. It performs differential time-domain reflectometry and transmission measurements to identify impedance discontinuities, shorts, opens, and other transmission line anomalies. The probe interfaces directly with Keysight DCA-X mainframes and TDR/TDT modules, delivering time and frequency-domain analysis of differential impedances and S-parameters down to the component level.

Technical Specifications

• Bandwidth: Up to 18 GHz


• Nominal Differential Impedance: 100 Ohms


• Probe Tip Spacing: 0.0 mm to 2.54 mm or 0.5 mm to 2.54 mm


• Probe Tips: Hardened, spring-loaded, independently movable in Z-axis; chamfered design for small pad contact; non-replaceable


• Durability: Greater than 7500 touchdowns at force ≤ 10 N


• Variable Risetime: Less than 20 ps to 1 ns (mathematically adjustable)


• Connector Interface: SMA Female

Key Features

• Differential TDR and TDT measurement capability


• S-parameter extraction (SDD11, SDD21, magnitude, phase, group delay)


• TDR calibration using shorts and loads for cable de-embedding


• Ergonomic handheld design with flexible cables and slim body


• Independent thumb-wheel tip adjustment for precise positioning


• Extended tips for target visibility during measurement

Measurement Capabilities

• Differential impedance characterization and return loss analysis


• Insertion loss measurement and signal integrity troubleshooting


• Detection of faults including shorts and opens


• Time and frequency-domain impedance analysis versus distance or frequency

Compatibility & Integration The N1021B integrates with Keysight DCA-X Wideband Oscilloscope Mainframes (86100C, 86100D) and differential TDR/TDT modules such as the 54754A. Optional 86100C/D-202 Enhanced Impedance and S-Parameter Software enables automated measurement and analysis workflows. Compatible also with other Keysight TDR/TDT modules and remote sampling heads including the N1055A 35/50 GHz multi-port unit.