WR-42 to 2.92mm (K) Female End-Launch Waveguide to Coax Adapter, UBR-220, 17.6-26.7 GHz

WR-42 to 2.92mm (K) Female Adapter for Full K-Band Operation

The QAXIAL W42KF-U220S adapter provides a transition between a WR-42 waveguide and a female 2.92mm coaxial interface. Designed with an end-launch configuration and straight geometry, it operates across the 17.6–26.7 GHz frequency range, covering the product’s full K-band operating range.

The coaxial interface, manufactured in accordance with MIL-STD-348A, has a nominal impedance of 50 Ω. On the waveguide side, the adapter complies with the EIA WR-42 and IEC R220 designations and features an EIA UG-597/U and IEC UBR-220 square cover flange.

Optimized RF Performance from 17.6 to 26.7 GHz

The W42KF-U220S is designed to provide a waveguide-to-coaxial transition with low insertion loss and excellent impedance matching across the entire operating frequency range.

The specified electrical performance includes a maximum VSWR of 1.20 and a maximum insertion loss of 0.35 dB. The datasheet also includes typical test plots for VSWR and insertion loss.

The insertion-loss measurement shown in the typical test data is performed using two adapters connected back-to-back. The insertion loss of a single adapter is obtained by dividing the total measured value by two.

Key Features

• 17.6–26.7 GHz frequency range
• Female 2.92mm coaxial interface
• 50 Ω nominal impedance
• EIA WR-42 / IEC R220 waveguide interface
• UG-597/U / UBR-220 square cover flange
• End-launch configuration with straight geometry
• VSWR ≤ 1.20
• Insertion loss ≤ 0.35 dB
• Rugged and repeatable mechanical design
• 1-year standard warranty

Construction and Materials

• Brass waveguide body with gray paint finish
• Stainless-steel connector body with passivated finish
• Beryllium-copper center contact with gold finish

The selected materials and finishes are intended to provide mechanical strength, interface stability and repeatable connections under the specified operating conditions.

Applications and System Integration

The adapter is intended for integration into RF systems requiring a transition between a WR-42 waveguide and a female 2.92mm coaxial connection across the 17.6–26.7 GHz frequency range.

• Connection of WR-42 waveguide components to compatible coaxial instrumentation
• Integration into K-band RF measurement and test setups
• Characterization of devices equipped with a WR-42 interface
• Assembly of RF subsystems with waveguide and coaxial interfaces
• Development, verification and validation of high-frequency components

Electrical and mechanical compatibility with the intended system configuration should be verified by considering the operating frequency, flange type and required coaxial interface.

Designed for an Extended Operating Temperature Range

The W42KF-U220S is specified for operation over a temperature range of -40 °C to +85 °C. Its rugged and repeatable mechanical design supports stable connections during installation, measurement and maintenance operations.

Specialized Technical Support

To verify the compatibility of the W42KF-U220S with a specific RF system, contact QAXIAL and provide the operating frequency range, waveguide interface, flange type and required coaxial-connection characteristics.

Technical support can assist with adapter selection and with the evaluation of the electrical and mechanical requirements for system integration.