Connection torque consideration for waveguide flange at millimeter-wave and terahertz frequencies

Connection torque of waveguide flange is one of major impact factor of measurement reproducibility in the range of millimeter-wave and terahertz frequencies. Generally, connection of waveguide flange is made by four screws specified in the MIL-DTL-3922/67C (UG-387). However, different values of connection torques are specified and used in the each society and industry. There is no existing specification for connection torque. In addition, the four screws connection have to spend time to make a connection/disconnection for waveguide flange, then the measurement stability for long time was concerned due to stability performance of vector network analyzer frequency extension module. The new connection clamp for waveguide flange has been proposed as a solution to make connection quickly[1]. This paper investigate a connection feature and its torque value to make good connection repeatability.