Agilent/Keysight 89431A

The Agilent/Keysight 89431A is a modular RF section that expands the measurement capabilities of the Agilent 89410A Vector Signal Analyzer. When paired with the 89410A, it creates the 89441A VSA system—extending frequency coverage to 2.65 GHz and enabling advanced signal analysis across R&D, manufacturing, and service applications. The 89431A delivers precise frequency conversion with excellent phase noise performance and input dynamic range for complex modulation analysis.

– Technical Specifications

Frequency Coverage:
• Input range: 2 MHz to 2650 MHz (2.65 GHz)
• Tuning resolution: 1.171875 MHz
• IF center frequency: 6 MHz
• IF bandwidth: 8 MHz

Frequency Accuracy & Stability (with standard high-precision reference):
• Initial accuracy: ±0.1 ppm
• Aging rate: ±0.015 ppm/month
• Temperature drift (0° to 55°C): ±0.005 ppm

Phase Noise Performance:
At 100 Hz offset, noise ranges from <–103 dBc/Hz (≤200 MHz) to <–87 dBc/Hz (1–2650 MHz). At 1 kHz offset: <–112 dBc/Hz to <–97 dBc/Hz across the same bands. At ≥10 kHz offset: <–116 dBc/Hz across all frequency ranges.

Input Specifications:
• Input range: –50 dBm to +25 dBm (in 5 dB steps)
• Maximum continuous input power: +25 dBm (300 mW)
• Maximum DC voltage: 25 V
• VSWR: 1.6:1 (≥–20 dBm); 1.8:1 (≤–25 dBm)
• Impedance: 50 Ω
• Connector: Type-N

Amplitude Accuracy:
• Conversion gain accuracy: ±2 dB (–20 dBm range, 6 MHz input)
• Input range attenuation accuracy: ±2.5 dB (≥–20 dBm); ±4 dB (≤–25 dBm)
• RF flatness (relative to 6 MHz): +2/–3.5 dB (≥–20 dBm); +3.5/–5 dB (≤–25 dBm)
• IF flatness (±4 MHz span): ±1.5 dB

Dynamic Range Performance:
• Harmonic distortion: <–75 dBc (≥–25 dBm range); <–54 dBc (≤–30 dBm range)
• Third-order intermodulation distortion (two tones, 6 dB below full scale, ≥10 MHz separation): <–8 dBc
• Third-order intercept (TOI): ≥33 dB above range

Output Characteristics:
• Nominal output level: –13 dBm at 6 MHz (single full-scale input signal)

– Key Features

• Spectral information mirroring within the IF bandpass
• LO spurious sidebands: 1 kHz offset); <–70 dBc to <–68 dBc (≤1 kHz offset, depending on frequency)
• Modular architecture integrates with 89410A VSA

– Compatibility & Integration

Designed as the RF front-end for the Agilent 89441A Vector Signal Analyzer system.