The Keysight 84904K is a programmable coaxial step attenuator designed for high-frequency testing up to 26.5 GHz. It offers exceptional attenuation repeatability of better than 0.03 dB and an outstanding operating life of over 5 million switching cycles per section. Using tantalum nitride thin-film attenuation cards on sapphire substrates, it achieves high attenuation accuracy and low SWR across its entire frequency range, making it highly suitable for integration into automatic test equipment (ATE) and precision RF systems.

Specifications

General

ParameterValue
Interfaces10-pin socket programming connector

Physical

ParameterValue
Power SupplySolenoid: 24 V nominal (Option 024) / 15 V nominal (Option 015) / 5 V nominal (Option 011)
Operating Temperature0 to +55 °C
Dimensions (W×H×D)36.5 mm × 32.2 mm × 114.3 mm (excluding connectors and brackets)
Weight0.229
Mounting Hole ThreadM3 × 0.5 (4.8 mm deep) and 4-40 UNC (4.8 mm deep)

RF Performance Specifications

ParameterValue
Frequency RangeDC to 26.5 GHz
Attenuation Range0 to 11 dB
Step Size1 dB
Nominal Impedance50 Ω
Insertion Loss (0 dB) Formula0.8 dB + 0.04 dB/GHz
Insertion Loss (0 dB) at 26.5 GHz< 1.86 dB
Maximum VSWR (DC to 12.4 GHz)1.30
Maximum VSWR (12.4 to 26.5 GHz)1.70
Maximum Input Power (Average)1 W
Maximum Input Power (Peak)100 W
Maximum Peak Power Pulse Width10 µs
Maximum Peak Power Duty Cycle0.001
RF Repeatability0.03 dB (maximum)
Switching Life (Cycles per Section)5 million
Number of Attenuator Sections4
Section Attenuation Values1, 2, 4, 4 dB
Attenuation Accuracy (1 to 2 dB, DC to 12.4 GHz)±0.3 dB
Attenuation Accuracy (1 to 2 dB, 12.4 to 26.5 GHz)±0.5 dB
Attenuation Accuracy (3 to 4 dB, DC to 12.4 GHz)±0.4 dB
Attenuation Accuracy (3 to 4 dB, 12.4 to 26.5 GHz)±0.6 dB
Attenuation Accuracy (5 to 6 dB, DC to 12.4 GHz)±0.5 dB
Attenuation Accuracy (5 to 6 dB, 12.4 to 26.5 GHz)±0.7 dB
Attenuation Accuracy (7 to 8 dB, DC to 12.4 GHz)±0.6 dB
Attenuation Accuracy (7 to 8 dB, 12.4 to 26.5 GHz)±0.8 dB
Attenuation Accuracy (9 to 10 dB, DC to 12.4 GHz)±0.7 dB
Attenuation Accuracy (9 to 10 dB, 12.4 to 26.5 GHz)±0.9 dB
Attenuation Accuracy (11 dB, DC to 12.4 GHz)±0.8 dB
Attenuation Accuracy (11 dB, 12.4 to 26.5 GHz)±1.0 dB

Electrical & Solenoid Control Specifications

ParameterValue
Solenoid Nominal Operating Voltage24 V (Option 024) / 15 V (Option 015) / 5 V (Option 011)
Solenoid Operating Voltage Range (24 V Option)20 to 30 V
Solenoid Operating Voltage Range (15 V Option)13 to 22 V
Solenoid Operating Voltage Range (5 V Option)4.5 to 7 V
Solenoid Switching Current (24 V Option)125 mA (per section)
Solenoid Switching Current (15 V Option)188 mA (per section)
Solenoid Switching Current (5 V Option)325 mA (per section)
Coil Resistance (24 V Option)190 Ω
Coil Resistance (15 V Option)80 Ω
Coil Resistance (5 V Option)17 Ω
Switching Speed (Maximum)20 ms
Recommended Drive Pulse Width20 to 30 ms (nominal 20 ms)
Solenoid Common Terminal ConfigurationCommon Pin 1 (plus 4 section lines & 4 indicator lines)
Control Interface Connector Type10-pin socket

Mechanical & Physical Specifications

ParameterValue
RF Connector Type (Standard)3.5 mm female (both ports)
RF Connector Option 1013.5 mm male on port 1, 3.5 mm female on port 2
Control Connector Pin Count10-pin
Mounting Position / OrientationAny
Recommended RF Connector Torque0.9 N·m (8 in-lb)

Environmental Specifications

ParameterValue
Non-Operating (Storage) Temperature Range-40 to +75 °C
Relative Humidity (Operating)95% RH at 40 °C (non-condensing)
Operating Altitude4,600 m (15,000 ft)
Non-Operating Altitude15,300 m (50,000 ft)
Shock Survival (Non-Operating)100 G, 6 ms

Ordering Information & Factory Options

ParameterValue
Operating Voltage Option 02424 V solenoid operating voltage
Operating Voltage Option 0115 V solenoid operating voltage
Operating Voltage Option 01515 V solenoid operating voltage
Connector Option 1003.5 mm female RF connectors on both ends
Compatible Electronic Attenuator Driver ModelsKeysight 11713B, Keysight 11713C

Performance

ParameterValue
Maximum Insertion Loss (0 dB, DC to 12.4 GHz)0.8 dB
Maximum Insertion Loss (0 dB, 12.4 to 18 GHz)1.1 dB
Maximum Insertion Loss (0 dB, 18 to 26.5 GHz)1.5 dB
Maximum VSWR (12.4 to 18 GHz)1.7
Maximum VSWR (18 to 26.5 GHz)1.8
Attenuation Accuracy (1 to 2 dB, 12.4 to 18 GHz)±0.4 dB
Attenuation Accuracy (1 to 2 dB, 18 to 26.5 GHz)±0.5 dB
Attenuation Accuracy (3 to 4 dB, 12.4 to 18 GHz)±0.5 dB
Attenuation Accuracy (3 to 4 dB, 18 to 26.5 GHz)±0.6 dB
Attenuation Accuracy (5 to 6 dB, 12.4 to 18 GHz)±0.6 dB
Attenuation Accuracy (5 to 6 dB, 18 to 26.5 GHz)±0.7 dB
Attenuation Accuracy (7 to 8 dB, 12.4 to 18 GHz)±0.7 dB
Attenuation Accuracy (7 to 8 dB, 18 to 26.5 GHz)±0.8 dB
Attenuation Accuracy (9 to 10 dB, 12.4 to 18 GHz)±0.8 dB
Attenuation Accuracy (9 to 10 dB, 18 to 26.5 GHz)±0.9 dB
Attenuation Accuracy (11 dB, 12.4 to 18 GHz)±0.9 dB
Attenuation Accuracy (11 dB, 18 to 26.5 GHz)±1.0 dB
Attenuation Temperature Coefficient< 0.0001 dB/dB/°C

Options

ParameterValue
RF Connector Option 0043.5 mm female
Control Interface Option 0088-inch ribbon cable with 14-pin DIP plug
Control Interface Option 01616-inch ribbon cable with 14-pin DIP plug

Environmental

ParameterValue
Operating Shock Survival8 g (11 ms, half-sine)
Operating Vibration Survival0.5 g (50 Hz to 2000 Hz)
Non-Operating Temperature Cycling-55 °C to +85 °C (5 cycles)
Non-Operating Relative Humidity95% RH @ 40 °C (for 5 days)

Power & Control

ParameterValue
Solenoid Drive StyleLatching (pulsed)
Solenoid LatchingMagnetic latching

Inputs & Outputs

ParameterValue
RF Connector GenderFemale (both ports)

Technology

Tantalum nitride thin-film on sapphire substrate

Applications

RF & microwave signal level control, receiver calibration, and integration into automated test equipment (ATE)