2. Reminder of the main protection techniques for immunity

The choice of protection depends on an understanding of their respective performances. They are often used in combination to take advantage of qualities that can complement each other, since no protection is universal with regard to possible aggressions and environments. There are three types of protection:

• filters ;

• skimmers ;

• shielding.

We won't go into software protection techniques here, nor into microwave techniques such as stubs and circulators.