HP / Agilent 70905A RF Section, 50 kHz to 22 GHz

The HP/Agilent 70905A RF Section is a modular front-end for HP 70000 series spectrum analyzer mainframes, covering 50 kHz to 22 GHz. This RF module performs signal downconversion and input conditioning, delivering a 21.4 MHz primary IF and a 321.4 MHz first IF output for further processing. The integrated low-noise mixer enables high dynamic range measurements across the entire frequency span.

Technical Specifications

• Frequency Range: 50 kHz to 22 GHz


• Input Attenuator: 0 to 70 dB, variable in 10 dB steps


• Primary IF Output: 21.4 MHz


• First IF Output: 321.4 MHz


• Input Impedance: 50 Ohm


• RF Input Connector: Type-N (f)


• 321.4 MHz Output/Input Connector: SMA


• IF Output Connector: SMB


• LO Signal Input Range: 3.0 to 6.6 GHz at +1.5 to +12 dBm

Key Features

• Low-noise mixer architecture for high dynamic range signal analysis


• 0 to 70 dB input attenuator with 10 dB step resolution for dynamic signal management


• First LO auxiliary output for tracking generator and external mixer interface module operation


• Automatic signal identification routine


• Dual IF outputs (21.4 MHz and 321.4 MHz) for flexible measurement configurations

Typical Applications

• RF and microwave signal analysis from 50 kHz to 22 GHz


• High dynamic range measurements requiring low-noise front-end conditioning


• Multi-stage downconversion in modular spectrum analyzer systems


• Integration with external tracking generators and mixer modules

Compatibility & Integration The 70905A is designed exclusively for the HP 70000 Modular Measurement System architecture. Compatible preselectors include the HP 70600A (2.7 GHz to 22 GHz) and HP 70601A (2.7 GHz to 26.5 GHz). Unlike the 70905B and 70906B variants, the 70905A includes an integrated input attenuator and operates as a complete standalone RF front-end without requiring a preselector.