The Keysight Q347B is a millimeter-wave noise source engineered for Q-band applications requiring calibrated noise signal generation across 33 to 50 GHz. It delivers highly precise broadband noise to devices and components under test, enabling accurate noise figure and gain characterization in radar, satellite communications, and high-frequency systems. The instrument operates by comparing ON and OFF noise power states—thermal agitation when powered down and active noise output when +28 V is applied—allowing noise figure meters to derive precise measurements of added noise and gain in the device under test.
Technical Specifications
• Frequency Range: 33 GHz to 50 GHz
• Excess Noise Ratio (ENR): 6–13 dB across band; 10–13 dB (33–42 GHz); 6–12.5 dB (42–50 GHz)
• Power Input: +28 V (±1 V) via BNC female connector
• Output Flange: Modified UG-383/U waveguide
• Maximum SWR: <1.57 (source off); <1.46 (source on)
• Reflection Coefficient: 0.22 (source off); 0.19 (source on)
• ENR Stability: Maintains exceptional stability over time, extending recalibration intervals and improving measurement accuracy
– Key Features
• Generates calibrated noise with ENR stability enabling extended operational periods between recalibration cycles
• Low reflection coefficient ensures minimal mismatch effects in high-frequency circuit characterization
• Dual-state noise output (ON/OFF) supports direct gain and noise figure extraction without external switching
• Modified UG-383/U waveguide interface minimizes insertion loss in Q-band pathways
– Typical Applications
• Noise figure measurements on millimeter-wave amplifiers and receivers
• Radar and satellite communication system characterization
• Device noise and gain validation in frequencies approaching 50 GHz
– Compatibility & Integration
• Works with Keysight 8970B Noise Figure Meter, NFA series, and X-Series (PXA, MXA) analyzers
• Operating and Service Manual and data sheets available
