What do most radars use in their waveguide system to prevent arcing?

Most radars utilize choke joints in their waveguide system to prevent arcing. Choke joints are a design feature incorporated into waveguides to minimize the risk of electrical discharge or arcing, which can occur due to high power levels in radar systems. By providing a barrier that alters the electric field distribution, choke joints help to maintain safe operating conditions within the waveguide.

The other choices do not serve the same function. While air compressors can be used in various systems, they do not directly prevent arcing in waveguides. Radio frequency filters are used to manage unwanted frequencies and signals but do not specifically address arcing issues in the waveguide. Radio frequency thermocouples involve temperature measurement and monitoring within systems but do not have a role in preventing electrical discharge. Therefore, choke joints are specifically designed for this task within radar systems.