Agilent/Keysight 85644A

The Agilent/Keysight 85644A is a tracking generator that operates synchronously with compatible spectrum analyzers and sweep oscillators to enable scalar network analysis. It generates a swept signal locked to the host instrument’s frequency, allowing direct measurement of amplitude response in RF components and systems without need for separate source and receiver sweeps.

– Technical Specifications

• Frequency Range: 300 kHz to 6.5 GHz
• Output Coupling: AC coupled
• Output Power: Selectable RF output levels
• Tracking Mode: Synchronizes with spectrum analyzer input frequency or sweep oscillator output frequency
• Offset Tracking: Supports frequency translation measurements for mixers and systems with propagation delay
• Control Interface: Front-panel configuration or HP-IB command access

– Key Features

• Locked tracking eliminates the need for dual-channel swept measurements, reducing test time
• High dynamic range performance inherited from tuned receiver architecture of connected spectrum analyzers
• Reduced spurious signal sensitivity due to selective input filtering of the host analyzer
• AC coupling prevents DC components from affecting RF measurements
• Offset tracking accommodates devices and circuits with frequency translation or group delay

– Typical Applications

• Filter and amplifier amplitude response characterization
• Frequency translation device analysis (mixers, converters)
• System gain and loss measurements
• Two-port scalar network analysis in production and field environments

– Compatibility & Integration

The 85644A interfaces with Agilent/Keysight 8560 Series, 8566A/B, and 8590 Series spectrum analyzers, as well as 8340A/B and 8350 Series synthesized sweepers and sweep oscillators. Configuration and control occur through front-panel menu selection or remote HP-IB commands, enabling integration into automated test systems.