The Agilent/Keysight 44478B is a dual 1×4 RF multiplexer module that provides bi-directional switching of high-frequency signals across a DC to 1.3 GHz bandwidth. This plug-in module delivers channel isolation exceeding 55 dB at 1 GHz, making it suitable for precision measurement applications including spectrum analysis, network analysis, and distortion measurement. The internal relay architecture uses a seven-relay tree structure per multiplexer to achieve high isolation and low VSWR performance.
Technical Specifications
• Frequency Range: DC to 1.3 GHz
• Channel Isolation: >55 dB at 1 GHz
• Insertion Loss: <1.9 dB at 1.3 GHz
• Characteristic Impedance: 75 Ohm
• Maximum Voltage: 42 V DC+AC peak
• Maximum Current: 1 A
• Maximum Power: 24 W or 24 VA per channel
• Maximum Scan Rate: 43 channels/second
• RF Connectors: Female BNC (module edge)
• Termination Connectors: Male SMB for 50/75 Ohm resistive termination
– Key Features
• Dual 1×4 multiplexer configuration with independent channel control
• Bi-directional switching enables flexible signal routing
• Seven-relay tree structure per multiplexer optimizes isolation performance
• Low VSWR design minimizes signal reflections
• On-board SMB connectors allow direct connection of off-channel termination resistors
• Female BNC connectors on all edge ports simplify integration with standard 50 Ohm test systems
– Typical Applications
• Multi-channel RF signal distribution and selection
• Broadband pulse signal switching
• Automated test setups requiring fast channel switching
• Dynamic range optimization through off-channel termination
– Compatibility & Integration
The 44478B integrates into the Agilent/Keysight 3488A Switch/Control Unit as Option 20, enabling modular expansion of switching capabilities within larger automated measurement systems.
