Agilent/Keysight 71209A – Spectrum Analyzer

The Agilent/Keysight 71209A is a modular microwave spectrum analyzer engineered for RF and microwave test applications across 100 Hz to 26.5 GHz, with optional extension to 40 GHz. This instrument delivers superior frequency accuracy, amplitude repeatability, and sensitivity through a flexible modular architecture within the Keysight 70000 series Modular Measurement System family. The 71209A achieves sensitivity of −138 to −128 dBm across its standard band and −155 to −150 dBm with preamplifier, making it ideal for demanding measurements in satellite communications and similar applications requiring measurement precision.

Technical Specifications

• Frequency range: 100 Hz to 26.5 GHz (optional to 40 GHz)


• External mixer capability supports coverage to 75 GHz using HP 11974 series mixers


• Frequency readout accuracy spans ±[1.0–2.5% of span + 10 Hz] depending on span and sweep parameters


• Frequency span accuracy: ±[1.0–4.0% of span plus reference accuracy term] based on span and sweep time Sensitivity & Signal Detection


• Standard sensitivity: −138 to −128 dBm


• Preamplifier-enhanced sensitivity: −155 to −150 dBm


• Resolution bandwidth: 10 Hz to 300 kHz (HP 70902A) or 100 kHz to 3 MHz (HP 70903A); ±20% accuracy


• Video bandwidth: 3 Hz to 300 kHz (HP 70902A) or 300 Hz to 3 MHz (HP 70903A); ±20% characteristic accuracy Sweep & Time Domain


• Sweep time: 10 ms to 1000 s continuous; 15 ms to 355 s with Agilent 70700A


• Fixed-frequency zero-span mode: 80 µs to 355 s with 800-point trace Calibration & Reference


• Three-year calibration cycle


• Frequency reference accuracy with Agilent 70310A: <1×10⁻⁷/year aging; <5×10⁻¹⁰/day aging (7-day average); <7×10⁻⁹ temperature drift


• Without 70310A reference: <3×10⁻⁶/year aging; <1×10⁻⁵ temperature drift

Key Features

• Modular design enabling tailored configurations for performance, footprint, and cost constraints


• Built-in external mixer interface for sub-millimeter-wave extension


• Agilent 8566B programming language compatibility for seamless test automation


• Amplitude frequency response to 2.9 GHz: ±1.5 dB to ±2.0 dB depending on temperature range and reference

Typical Applications

• Satellite communications system characterization


• Microwave component and subsystem testing


• Automated RF measurements and production testing

Compatibility & Integration The 71209A integrates into the Keysight 70000 series modular measurement ecosystem, supporting optional modules including the 70700A for extended sweep capability, 70902A and 70903A bandwidth modules, and 70310A precision frequency reference for enhanced stability and aging performance.