The Agilent/Keysight 8981A is a Vector Modulation Analyzer that measures and analyzes modulation characteristics across digital communication and radar signals. It provides quantitative data and visual representations of modulation parameters, enabling rapid identification and measurement of signal impairments. The instrument delivers coherent phase and amplitude analysis, constellation mapping, and statistical quality metrics essential for signal optimization and system verification across cellular, satellite, and radar applications.
Technical Specifications
• Frequency Range: DC to 350 MHz
• IF Input Frequency Range: 50 MHz to 200 MHz
• Baseband Bandwidth: 35 MHz (internal filters) / 100 MHz (external filters)
• Demodulation Bandwidth: Up to 70 MHz for communications signals
• Quadrature Error: Less than 0.5°
• Amplitude Imbalance: Less than 0.1 dB
• Digitizing Resolution: 12-bit for HP-IB measurements
• Weight: Approximately 25 lbs
– Key Features
• Vector modulation analysis with coherent phase and amplitude measurement
• Quadrature error and lock angle error quantification
• Constellation analysis supporting QPSK, 16QAM, 64QAM, and 256QAM
• Unintentional modulation on pulse (UMOP) identification via delta-phase measurement
• Vector-demodulated SAW chirp signal display
• Multiple visualization modes: vector diagram, versus time, Q vs. F, I/Q channels, and 3D display
• Automatic internal and external demodulator calibration
• Statistical measures of system quality
– Typical Applications
• Cellular signal verification and optimization
• Satellite communication system analysis
• Radar signal characterization
• Digital communication system troubleshooting and design validation
– Compatibility & Integration
• HP-IB interface for remote measurements
• Coherent reference input for IF measurements
• I/Q outputs compatible with receiver demodulator outputs
• IF output connection to transmitter IF stages
• Supports analysis of analog I/Q signals and standard digital communication modulation schemes
