The Keysight Technologies (formerly Agilent HP) 84904L is a high-performance coaxial programmable step attenuator operating from DC to 40 GHz. Designed for high reliability and integration in automated test equipment (ATE) systems, it offers an attenuation range of 0 to 11 dB in precise 1 dB steps. The unit utilizes miniature thin-film tantalum nitride attenuation cards on sapphire substrates to achieve exceptional accuracy, repeatability, and low SWR across its ultra-wide operating frequency.

Specifications

Physical

ParameterValue
Power Supply24 VDC / 15 VDC / 5 VDC solenoid actuation (option dependent)
Operating Temperature0 to +55 °C
Weight0.29 kg

RF Performance

ParameterValue
Frequency RangeDC to 40 GHz
Attenuation Range0 to 11 dB
Attenuation Step Size1 dB
Nominal Impedance50 Ω
Insertion Loss at 0 dB0.8 dB + 0.04 dB/GHz
Maximum Insertion Loss (at 40 GHz)2.4 dB
Maximum SWR (DC to 12.4 GHz)1.3
Maximum SWR (12.4 to 34 GHz)1.7
Maximum SWR (34 to 40 GHz)1.8
Attenuation Repeatability0.03 dB maximum
Maximum Continuous RF Input Power (Average)1 W
Maximum Peak RF Input Power100 W
Attenuation Card MaterialThin-film tantalum nitride
Attenuation Card SubstrateSapphire

Mechanical & Connector

ParameterValue
RF Connector Type (Standard)2.4 mm female
RF Connector Options2.4 mm (male/female) or 2.92 mm (male/female)
Operating Life5 million switching cycles per section

Electrical & Actuation

ParameterValue
Solenoid Nominal Voltage Options24 V, 15 V, 5 V
Switching Speed (Actuation Time)20 ms maximum

Performance

ParameterValue
Number of Attenuator Sections4
Attenuator Section Values1 dB, 2 dB, 4 dB, 4 dB
Attenuation Accuracy (DC to 12.4 GHz)±0.35 dB (1 to 4 dB), ±0.55 dB (5 to 8 dB), ±0.70 dB (9 to 11 dB)
Attenuation Accuracy (12.4 to 34 GHz)±0.45 dB (1 to 4 dB), ±0.65 dB (5 to 8 dB), ±0.85 dB (9 to 11 dB)
Attenuation Accuracy (34 to 40 GHz)±0.55 dB (1 to 4 dB), ±0.85 dB (5 to 8 dB), ±1.05 dB (9 to 11 dB)

Power & Solenoid

ParameterValue
Solenoid Switching Current (Standard 24 V)125 mA (nominal per section)
Solenoid Switching Current (Option 011 5 V)300 mA (nominal per section)
Solenoid Switching Current (Option 015 15 V)188 mA (nominal per section)
Solenoid Coil Resistance (Standard 24 V)190 Ω
Solenoid Coil Resistance (Option 011 5 V)17 Ω
Solenoid Coil Resistance (Option 015 15 V)80 Ω

Environmental

ParameterValue
Storage Temperature-55 to +85 °C
Operating AltitudeUp to 4,600 m (15,000 ft)
Storage AltitudeUp to 15,200 m (50,000 ft)

Technology

Thin-film tantalum nitride on sapphire

Applications

Coaxial programmable step attenuation for RF and microwave test systems