Keysight (Agilent) 346C

The Keysight 346C is a broadband noise source engineered for precise noise figure measurements across RF and microwave frequencies. It delivers stable, calibrated noise signals essential for characterizing amplifiers, receivers, and RF circuits with minimal measurement uncertainty. Individual ENR calibration data supplied on floppy disk enables direct integration with Keysight noise figure analyzers and spectrum measurement platforms.

Technical Specifications

• Frequency Range: 10 MHz to 26.5 GHz


• Excess Noise Ratio (ENR): 15 dB nominal – 10 MHz to 12 GHz: 16 dB ENR (12 to 16 dB limits) – 12 GHz to 26.5 GHz: 17 dB ENR (14 to 17 dB limits)


• VSWR: <1.35:1


• Characteristic Impedance: 50 Ω


• RF Output Connector: 3.5 mm (male)


• Power Supply: 28 V DC, 45 mA typical (source ON)


• Maximum Reverse Power: 1 W


• Operating Temperature Range: 0°C to 55°C


• Physical Dimensions: 140 mm (H) × 21 mm (W) × 30 mm (D)


• Shipping Weight: 2 lb

Key Features

• Low VSWR (<1.35:1) minimizes signal reflections and measurement uncertainty


• Individually calibrated ENR values at specific frequencies


• Dual-level ENR performance optimized across 10 MHz to 26.5 GHz coverage


• BNC input bias connector for external power control


• Produces active noise output when 28 V DC is applied; residual thermal noise present when powered down


• Compact form factor enables laboratory and field deployment

Typical Applications

• Noise figure measurement of low-noise amplifiers (LNAs)


• Receiver sensitivity characterization


• RF component validation and design verification


• System-level noise performance assessment

Compatibility & Integration The 346C integrates with Keysight's NFA Series Noise Figure Analyzers, ESA-E, PNA-X, PSA-Series, and X-Series instruments (PXA, MXA, EXA, CXA). Optional configurations include the K01 (1 GHz to 50 GHz, 2.4 mm connector), K40 (40 GHz, 2.4 mm, 6 dB attenuator), and H01 (21 dB ENR, APC 3.5 mm connector).