The Keysight 11904C is a metrology-grade RF adapter engineered for precision interconnection of 2.4 mm and 2.92 mm connectors in high-frequency test systems. It delivers minimal insertion loss and excellent return loss performance across DC to 40 GHz, making it suitable for calibration-grade measurements and repeatability-critical applications in RF and microwave environments.
Technical Specifications
• Frequency Range: DC to 40 GHz
• Return Loss: > 24 dB
• Repeatability: −40 dB
• Electrical Length: 11.3 mm (0.45 in)
• Overall Length: 13.3 mm (0.52 in)
• Diameter: 9.0 mm (0.35 in)
• Connector 1: 2.4 mm Male
• Connector 2: 2.92 mm Female
– Key Features
• Metrology-grade construction ensures performance suitable for calibration applications
• 2.4 mm male connector features increased outer wall thickness for enhanced durability relative to SMA and 2.92 mm designs
• 2.92 mm female connector rated to 40 GHz and cross-compatible with SMA and 3.5 mm adapters
• Compact form factor: 13.3 mm overall length with 9.0 mm diameter
• High return loss specification (> 24 dB) minimizes reflections in precision measurement setups
– Typical Applications
• Calibration and standards work requiring highest-grade repeatability
• Test fixture construction in microwave and RF laboratories
• Connector interface verification and characterization to 40 GHz
• Measurement system integration where signal path integrity is critical
– Compatibility & Integration
The 2.4 mm connector interfaces with SMA, 3.5 mm, and 2.92 mm connectors through precision adapters. The 2.4 mm design—developed by HP, Amphenol, and M/A COM—operates to 50 GHz and is available in general purpose, instrument, and metrology grades. The 11904C’s metrology grade designation targets applications demanding the highest performance and measurement repeatability.

















