Agilent/Keysight 3048A

The Agilent/Keysight 3048A Phase Noise Measurement System is a modular instrument platform engineered for precision phase and AM noise characterization across microwave frequencies. It integrates an HP 11848A Phase Noise Interface box with an HP 3561A Dynamic Signal Analyzer and control software to deliver calibrated noise measurements with traceable accuracy.

Technical Specifications

Frequency coverage spans 5 MHz to 18 GHz in standard configuration, with Option 201 extending residual phase noise measurements to 18 GHz via a tunable microwave reference. Special options accommodate frequencies below 5 MHz and up to 110 GHz. Offset frequency range extends from 0.01 Hz to 40 MHz; special options cover 0.001 Hz to 1 GHz. Accuracy is specified at ±2 dB for offsets from 0.01 Hz to 1 MHz and ±4 dB from 1 MHz to 40 MHz. The system applies automatic corrections for signal path losses, phase-lock-loop effects, and phase detector nonlinearity. Phase detector inputs accommodate +15 dBm to +23 dBm levels at 5 MHz to 1.6 GHz, 0 dBm minimum at 1.2 GHz to 18 GHz. Option 201 phase detectors accept 0 dBm to +7 dBm at 12 GHz to 18 GHz.

Key Features

• HP 11848A interface provides integrated phase detectors, amplifiers, filters, and RF switching


• HP 3561A analyzer delivers Fourier-type spectral analysis with configurable data averaging and fast acquisition


• Dual measurement capability: phase noise and AM noise using internal detectors or external crystal detectors


• Built-in signal sources enable functional verification of signal-conditioning circuits


• HP-IB commands allow programming of external voltage-tunable reference sources


• Internal baseband noise input accommodates external phase detector outputs

Typical Applications Phase noise characterization of oscillators, synthesizers, and amplifiers. AM noise assessment of microwave components. Residual noise measurement with external references. Frequency sources up to 110 GHz via external detectors.

Compatibility & Integration Option 202 rackmount configuration integrates the interface box, analyzer, and signal cabling within a single rack enclosure with dedicated fan and power module. Compatible with external signal generators for reference source flexibility.