The HP/Agilent 54121T is a 20 GHz digitizing oscilloscope system built for high-speed signal capture and analysis in R&D, manufacturing, and service environments. The instrument combines the 54120B Color Display Mainframe with the 54121A Four Channel Test Set to deliver precise time-domain measurements, built-in TDR/TDT capability, and automated pulse characterization across DC to 20 GHz bandwidth.
## Technical Specifications
**Bandwidth & Timing**
• Bandwidth: DC to 20 GHz
• Rise time: 17.5 ps
• Time interval resolution: 0.25 ps
• Time interval accuracy: 10 ps + 0.1% of reading
• Trigger and time base jitter (RMS): < 2.5 ps + 5E-5 × delay setting
**Vertical Measurements**
• Vertical accuracy: 0.4%
• Vertical resolution: 32 microvolts
• Vertical deflection factor: 1 mV/div to 80 mV/div
• Noise floor: 2 mV rms
**Horizontal Measurements**
• Time base range: 10 ps/div to 1 s/div
**Triggering**
• Edge trigger to 2.5 GHz
• True triggering to 18 GHz with test set
**Step Generator**
• Rise time: typically 35 ps
• Flatness: typically 1%
## Key Features
• Built-in TDR/TDT system with test-system error normalization
• Time and voltage histograms for jitter and noise characterization
• Eye pattern analysis capability
• Automatic pulse parameter measurement functions
• Fully HP-IB programmable interface
• Color display mainframe
• Four-channel test set configuration
## Typical Applications
• High-speed device and circuit characterization
• High-speed telecom signal analysis
• Microwave design validation
• Interconnect characterization
• Network analysis
• Waveform statistics and jitter measurement
## Compatibility & Integration
The system integrates a step generator within the test set. External TDR/TDT sources—such as the Picosecond Pulse Labs 4015B—can extend measurement capabilities. RF accessory kit availability varies by configuration. Programming Reference Manual and Front-Panel Reference Manual documentation is available.
