In Episode 13, the season finale of The Americans the spying for a program called “Echo” plays a role. In the show universe Echo computes the strange angles of stealth planes, reflecting Radar rays somewhere else but not to the sending radar station.
Searching for phrases in the program links to this code snippet, a file from “MATLAB Simulations for Radar Systems Design”, from 2003. I’m far from being an expert, but it seems that the program is generalized signal analysis of radar signals, nothing stealth-related.
Also: MATLABs version 1.0 was in 1984 but the current timeline of the show should be somewhere in 1982.