Re-visiting the repeatability issues of the type-N connectors

The type-N coaxial connector was introduced to the market in 1942. The precision type N connector that is in use today emerged in 1965. The repeatability for the type N connectors is a key factor for improved measurement accuracy. There were several studies being reported on this subject for the last few years. They have tried to resolve the repeatability and reproducibility problems by focusing on the following issues: the effect of pin gap, slotted vs. slotless female connectors, connector coupling technique, connector defect modeling and theory, connector orientations, and etc. No conclusive solutions can be made on how to reduce the un-repeatability of type N connectors. During our study, we have come across a better approach of using the power sensor testing system to monitor the mating of connector pair. It is now used to improve the measurement repeatability. The standard deviation of the connector repeatability can be controlled within 0.1% for the whole frequency range.