Agilent / Keysight 8559A 21 GHZ Spectrum Analyzer

The Agilent/Keysight 8559A is a plug-in spectrum analyzer module for compatible display mainframes such as the HP 853A or 180-series. It delivers broadband RF and microwave analysis from 0.01 GHz to 21 GHz with direct CRT readout in dBm, making it suitable for research, production, and field service environments.

Technical Specifications

• Frequency range: 0.01 GHz to 21 GHz


• Selectable spans from 10 kHz to 200 MHz/division in 1–2–5 sequence


• Zero-span mode enables time-domain observation of signal modulation


• Tuning accuracy (0.01–3 GHz): ±(1 MHz + 0.3% of center frequency)


• Tuning accuracy (3–21 GHz): ±(5 MHz + 0.2% of center frequency)


• Frequency span accuracy: ±5% of displayed separation


• Frequency readout resolution: 1 MHz Resolution & Selectivity


• Eight selectable resolution bandwidths from 1 kHz to 3 MHz in 1–3 sequence


• Resolution bandwidth accuracy: ±15% (3 MHz: <+30%)


• 60 dB / 3 dB selectivity ratio: <15:1


• Video filter MAX position: approximately 1.5 Hz for noise measurement Amplitude Performance


• Amplitude range: –111 dBm to +30 dBm


• Absolute amplitude calibration via direct CRT readout without external standards


• Reference level selectable: 10 dB/div, 1 dB/div, or linear scale


• Gain compression: <0.5 dB at +10 dBm input with 0 dB attenuation


• Residual responses: <–90 dBm (0.01–3.06 GHz) at 0 dB attenuation, no signal Spectral Stability


• Residual FM: 30 kHz from center frequency (1 kHz RBW, full video filtering) Input Characteristics


• Input impedance: 50 Ω nominal


• Input SWR: Typically <2.0 at 0 dB attenuation; <1.3 at 10 dB attenuation

Key Features

• Independent or coupled resolution bandwidth and frequency span control


• Automatic sweep time adjustment maintains amplitude calibration across all configurations


• Plug-in module architecture integrates with HP 853A and 180-series mainframes

Typical Applications RF and microwave research, production testing, field service, and signal characterization from DC monitoring through microwave frequencies.

Compatibility & Integration Designed for use with compatible HP display mainframes including the 853A and 180-series.