Agilent/Keysight N4985A

The Keysight N4985A series comprises high-performance broadband system amplifiers engineered for RF and microwave applications spanning baseband to millimeter-wave frequencies. Each model delivers high gain and output power across its designated frequency range, with self-contained construction powered by standard AC mains. The series accommodates diverse test scenarios: bench-top laboratory characterization, production-line validation, and time/frequency-domain measurements. Multiple variants—N4985A-P15, N4985A-P25, N4985A-S30, and N4985A-S50—provide tailored frequency coverage and performance metrics for specific amplification requirements.

– Technical Specifications

• Frequency Coverage (model-dependent):
– N4985A-P15: 10 MHz to 50 GHz
– N4985A-P25: 2 GHz to 50 GHz
– N4985A-S30: 100 kHz to 30 GHz
– N4985A-S50: 100 kHz to 50 GHz

• Gain: Up to 27 dB at 20 GHz (N4985A-P15, ±2 dB flatness); 30 dB gain to 26 GHz across series variants

• Output Power:
– 22 dBm at 50 GHz
– Greater than 20 dBm across frequency range
– 1 W (30 dBm) Psat to 10 GHz
– 26 dBm P₋₁dB and 29 dBm Psat at 20 GHz

– Key Features

• Built-in bias power supplies eliminate external supply dependencies
• Compact form factor enables close placement to device under test or fixture
• Self-contained design integrates into existing benchtop or automated test setups

– Typical Applications

• Saturated RF amplifier characterization
• Traveling Wave Tube (TWT) amplifier drive stages
• Antenna system amplification and R&D
• RF source amplification and mixer local oscillator chains
• Noise figure measurement (LNA and full-system configurations)
• Pulse and time-domain amplification
• Digital communication system validation
• General-purpose RF gain blocks

– Compatibility & Integration

Optional optical application tuning modules—N4985A-OA3 (S30 option) and N4985A-OA5 (S50 option)—extend flexibility for specialized measurement environments. Standard AC power connection ensures straightforward deployment in laboratory and production facilities.