Improved Design of Flange Mount Coaxial Connector With Low Passive Intermodulation Distortion

Imperfect electrical connections cause multiple problems in radio-frequency (RF) measurements, with passive intermodulation (PIM) being the most common one. This article proposes a new design approach to reduce the PIM distortion caused by the imperfect electrical connection in flange mount coaxial connectors. The proposed approach employs a flexible ring embedded in the outer conductor of the flange mount coaxial connector to improve the reliability of the metal electrical connection. A simulation model is further developed to analyze the effects of the embedded ring on the signal transmission performance. The effectiveness of the proposed approach is verified by experiments, demonstrating that the improved design can not only decrease the PIM level by up to 9 dB, but also show a good reliability and stability in the conditions requiring repeated connection and disconnection, and thus, this method has the potential for the application of all flange mount devices.