The Keysight (Agilent/HP) 355C is a high-precision manual step attenuator designed for operation from DC to 1000 MHz (1 GHz). Utilizing cam-actuated microswitches to insert and remove attenuator sections, this compact and rugged unit maintains short lead lengths to minimize stray capacitances, inductances, and phase shifts. It provides reliable attenuation from 0 to 12 dB in 1 dB steps and can be cascaded in series with the 355D to extend the range up to 132 dB.

Specifications

Physical

ParameterValue
Dimensions (W×H×D)54 mm × 67 mm × 152 mm
Weight0.68 kg

RF & Electrical Specifications

ParameterValue
Frequency RangeDC to 1 GHz
Attenuation Range0 to 12 dB
Attenuation Steps1 dB steps
Nominal Impedance50 ohms
Maximum SWR (DC to 250 MHz)1.2
Maximum SWR (250 to 500 MHz)1.3
Maximum SWR (500 MHz to 1 GHz)1.5
Maximum Insertion Loss at 0 dB0.2 dB + 2.3 dB/GHz
Maximum Average Input Power0.5 W
Maximum Peak Input Power350 W
Overall Accuracy (DC to 500 MHz)±0.25 dB
Overall Accuracy (DC to 1000 MHz)±0.35 dB
Overall Accuracy (at 1000 Hz)±0.1 dB

Mechanical & Physical Characteristics

ParameterValue
Standard Connector TypeBNC female
Optional Connector TypesType-N female, TNC female
Control MethodManual (cam-actuated microswitches)
Port BidirectionalityEither terminal may be connected as input or output
Series CompatibilityCan be connected with the 355D in series to provide precision attenuation in 1 dB steps from 0 to 132 dB

Accessories

ParameterValue
Compatible Interconnect KitHP 11716A (Type-N), HP 11716B (BNC)

Performance

ParameterValue
Combined Range with HP 355D0 to 132 dB in 1 dB steps (when connected in series with HP 355D)

Technology

Coaxial Step Attenuator

Applications

Precision RF signal attenuation and level control