Keysight (Agilent) 355D Manual Step Attenuator, DC to 1000 MHz

The Keysight (Agilent) 355D is a manual step attenuator providing precise RF signal attenuation across DC to 1 GHz. It delivers 0 to 120 dB of attenuation in discrete 10 dB steps, ideal for testing, measurement, and signal conditioning applications. The unit employs resistor pi networks and cam-actuated microswitches to achieve low phase shift and excellent repeatability. Its compact, rugged construction minimizes stray pickup and signal leakage, with all components rigidly positioned and well-shielded. Either terminal may serve as input or output, making it flexible for bidirectional signal paths.

– Technical Specifications

• Frequency Range: DC to 1 GHz
• Attenuation Range: 0 to 120 dB
• Attenuation Step: 10 dB per section
• Insertion Loss (at 0 dB): 0.2 dB + 2.3 dB·GHz
• Maximum VSWR: 1.2 (DC to 250 MHz), 1.3 (to 500 MHz), 1.5 (to 1 GHz)
• Repeatability: 0.03 dB maximum over 0.5 million cycles per section
• Maximum RF Input Power: 0.5 W average; 350 W peak (10 µs pulse width maximum)
• Impedance: 50 ohms
• Connectors: BNC female (standard); Type-N female and TNC female optional

– Key Features

• Resistor pi network design for minimal phase shift
• Cam-actuated microswitches with short lead lengths reduce stray capacitance and inductance
• Manual step control with excellent attenuation repeatability
• Meets MIL Standards, ANSI/IEEE Standards, RTCA/DO-160, IEC CISPR, EN, ISO, Boeing, and FCC Standards

– Typical Applications

RF signal attenuation, precision testing, measurement systems, and signal conditioning where accurate, repeatable level control is required.

– Compatibility & Integration

The 355D connects in series with the Keysight (Agilent) 355C attenuator to achieve 1 dB step resolution from 0 to 132 dB using standard UG-491A/U BNC (m)-to-BNC (m) adapters.