One of the mysteries of the English language finally explained.
A junction of a rectangular waveguide consisting of an E-plane and an H-plane junction combined at the same point, giving four ports such that a wave entering one port divides between the two adjacent ports without appearing at the opposite one.
1940s; earliest use found in Frederick Terman (b. 1900).
In this article we explore how to impress employers with a spot-on CV.