Agilent/Keysight 34905A

The Keysight/Agilent 34905A is a dual 4-channel RF multiplexer module that routes high-frequency and pulsed signals between test instruments and devices under test. Each of the two independent 1×4 multiplexers features a common ground with channels organized in a tree structure for high isolation and low VSWR. The module supports 50-ohm impedance applications and delivers broadband switching capabilities up to 2 GHz when connected directly to SMB inputs, or up to 1 GHz with SMB-to-BNC adapter cables. Only one channel per bank can be closed at a time; engaging one channel automatically opens the previously active channel. One channel in each bank remains connected to COM, and channels can only be closed on this module—open states are achieved by closing another channel in the same bank.

– Technical Specifications

• Configuration: Dual 4-channel (two independent 1×4 multiplexers)
• Impedance: 50 Ohm
• Bandwidth: Up to 2 GHz (SMB direct connection); up to 1 GHz (with SMB-to-BNC adapter cables)
• Connectors: On-board SMB connectors with included SMB-to-BNC adapter cables (10 cables supplied)
• Switching: Single-pole multi-throw design; one channel per bank always connected to COM

– Key Features

• Tree-structured channel organization for high isolation and low VSWR
• Automatic switching—engaging one channel opens the previously closed channel
• Cascadable architecture—multiple 34905A modules create larger multiplexer configurations, including stubless 16:1 multiplexers within a single frame
• Common ground per bank ensures signal integrity across channels

– Typical Applications

• Multi-channel RF signal routing between signal generators, oscilloscopes, and spectrum analyzers
• High-frequency pulsed signal switching
• Broadband test automation requiring multiple device access points

– Compatibility & Integration

The 34905A integrates directly into Keysight/Agilent mainframes: 34970A Data Acquisition/Switch Unit, 34972A Data Acquisition/Switch Unit, and 34980A Multifunction Switch/Measure Unit. Ship weight is approximately 4 lbs.