Agilent/Keysight 8591EM

The Agilent/Keysight 8591EM is a portable EMI analyzer that combines spectrum analyzer and EMI receiver functionality for pre-compliance testing and electromagnetic interference diagnostics. Built on the Agilent 8590 E-series platform, this stand-alone instrument automates EMC precompliance measurements without requiring external computers or software. It measures and stores up to 239 signals across specified frequency ranges, applies limit-line comparisons against two regulatory standards plus user-defined margins, and executes predefined CISPR band routines with correct video and resolution bandwidths.

Technical Specifications

• Frequency range: 9 kHz to 1.8 GHz


• DC-coupled operation: 9 kHz to 1.8 GHz


• AC-coupled operation: 1 MHz to 1.8 GHz


• Frequency sweep time: 20 µs to 100 s (span 0 Hz, >1 kHz)


• Standard frequency accuracy: 7.5 ppm; optional precision reference improves to 1 × 10⁻⁸


• Frequency stability with precision reference: 1 × 10⁻⁸ Amplitude Characteristics


• Displayed average noise level: approximately -115 dBm (–115 to –113 dBm)


• Amplitude range: -115 dBm to +137 dBµV


• Maximum safe input: +30 dBm average continuous (attenuator ≥10 dB), +30 dBm peak pulse, 25 Vdc


• Reference level range: -115 to +30 dBm (50 Ω)


• Calibrated amplitude range: +30 to +130 dBm (with Option 130)


• Calibrated on-screen display: 70 dB dynamic range Resolution and Bandwidth


• Resolution bandwidths: 1 kHz to 3 MHz standard; optional 30 Hz to 3 MHz (1, 3, 10 sequence)


• EMI bandwidths: 200 Hz, 9 kHz, 120 kHz, 1 MHz (6 dB); narrow bandwidths (30, 100, 200 EMI, 300 Hz) available on optional circuit card


• Video bandwidth: 1 Hz to 1 MHz (1, 3, 10 sequence)


• RBW switching uncertainty: ±0.4 dB (3 kHz to 3 MHz); ±0.5 dB (1 kHz)

Key Features

• Dual-mode operation: EMI analysis and spectrum analysis


• Automated signal detection and documentation up to 239 signals per measurement session


• Dual limit-line display for regulatory compliance comparison


• CISPR band setup automation with integrated bandwidth correction


• Amplitude correction built-in


• Supports products with clock frequencies to 108 MHz

Typical Applications

• EMC pre-compliance testing


• Diagnostic EMI measurements


• Radiated and conducted emissions screening


• Product development and troubleshooting

Compatibility & Integration The 8591EM operates as a fully autonomous platform, eliminating dependency on external software or host computers for automated EMI workflows.