This paper is a parametric study of active satellite repeater communications links in a jamming environment. Under heavy jamming conditions with an earth coverage satellite antenna, the communication effectiveness of the link is presented as a oneparameter family of curves. A crucial parameter which is a figure of merit of the link is

, where

is the power radiated by the active satellite repeater,

is the diameter of the receiving dish and

is the receiving system noise temperature. Jamming-limited and thermal noise-limited conditions are identified and their implications are discussed.