1. Physical Structure of MMCX Interface:

The MMCX interface consists of a plug and a jack. The plug includes a center contact (inner pin) and a shell, while the jack contains a center socket (inner hole) and a shell. In the MMCX interface, the center contact or socket is typically defined as the signal line, often referred to as the "positive" pole, while the shell is usually defined as the ground line or negative pole.

2. Electrical Characteristics of MMCX Interface:

In terms of electrical connection, the polarity of the MMCX interface can also be determined by measuring voltage. Generally, the positive pole has a higher voltage than the negative pole. Therefore, the polarity of the MMCX interface can be determined using a voltmeter.

However, it is important to note that unlike a direct current power source, the polarity of the MMCX interface is not clearly defined based on its physical structure or electrical characteristics alone. This is because the MMCX interface transmits RF signals and operates differently from a DC power source. Therefore, in practical applications, it is more common to refer to the physical structure of the MMCX interface to determine the "positive" and "negative" poles.

In conclusion, determining the polarity of the MMCX interface primarily relies on its physical structure, with the center contact or socket serving as the "positive" pole and the shell as the "negative" pole. In actual usage, users should refer to the specific device's interface definition and user manual for detailed identification and operation to ensure proper connection and normal operation of the equipment.