Agilent/Keysight N4903B

The Keysight N4903B is a multi-channel serial Bit Error Rate Tester (BERT) designed for R&D and validation of high-speed digital communication systems. It delivers precise characterization and stress testing of transceiver modules and devices with serial I/O ports across industry-standard interfaces. The instrument combines pattern generation, error detection, and integrated jitter injection to validate receiver tolerance and transmitter performance in advanced digital interfaces.

Technical Specifications

• Pattern Generator and Error Detector: 150 Mb/s to 7 Gb/s, or up to 12.5 Gb/s


• Extended capability with option: 14.2 Gb/s


• Maximum with 2:1 multiplexer and demultiplexer: 28.4 Gb/s Jitter Injection and Measurement


• Integrated, calibrated jitter sources exceeding 0.5 UI


• Random Jitter (RJ): 0 to 20 mUI rms (0 to 280 mUI pp)


• Periodic Jitter (PJ1 + PJ2) with Option D14 (>12.5 Gb/s): 0 to 2.0 UI


• Jitter modulation frequency: 1 kHz to 100 MHz


• Jitter types: RJ, RJ-LF, RJ-HF, PJ1, PJ2, Sine Jitter, Bursty Jitter, Inter-Symbol Interference, sinusoidal interference, triangular and arbitrary Spread Spectrum Clocking, residual SSC Clock and Data Recovery


• Built-in CDR with tunable, compliant loop bandwidth


• Half-rate clocking with variable duty cycle (Option 003)


• Operation at full or half bit-rate Pattern Generation


• PRBS and user-defined patterns


• 60-block pattern sequencer with real-time switching via auxiliary input


• Independent PRBS and pattern generation on auxiliary data output

Key Features

• Bit Error Rate, BER Contour, and automated jitter tolerance measurements


• Total Jitter with RJ/DJ separation and Eye Diagram analysis


• Eye Mask testing and Frame Error Rate (FER) detection


• Symbol Error Rate (SER) on coded and retimed data streams


• Pattern Capture functionality


• Differential I/Os optimized for serial bus standards

Typical Applications

• Receiver jitter tolerance characterization


• Transmitter signal quality validation


• Serial I/O compliance testing


• Device stress testing and margin analysis

Compatibility & Integration Differential I/O interfaces designed to match serial bus standards. Supports Option 003 for half-rate clocking and duty cycle distortion testing.