Radar slip ring is a device that transmits electric signals and energy between the rotating parts of antenna frame and the stationary parts by slip or rolling contact, electrostatic coupling or electromagnetic coupling of conductive parts. There are driving elements, measuring elements and control elements on the rotating parts. Control signals and power supply must be transmitted to them from the engine room.  This requires a variety of slip ring components to transmit signals and energy. Some radars need to rotate more than 100 connections. Slip ring assembly can be divided into low frequency slip ring, medium frequency slip ring and high frequency rotating hinge according to the frequency of transmission signal. The electrical performance indexes of slip ring assembly are insulation resistance, contact resistance, dielectric strength and crosstalk. For intermediate frequency sliding ring, shielding, impedance matching, noise voltage and so on should be considered when the frequency is high. In the structural design, the first thing is to ensure reliable contact and continuous connection of all lines. Therefore, it is required that the material used in the brush has good conductivity, proper pressure on the slip ring, small eccentricity and sway, good wear resistance, small friction moment and easy maintenance.