A new dual-directional coupler, Model 504020006 is a multi-purpose, stripline design that exhibits excellent coupling of 6 dB over the 4.0 to 20 GHz (C- through Ka-) frequency bands. These coaxial dual-directional couplers are 4-port couplers that are the combination of two 3-port couplers having their main lines cascaded. This dual-directional design, two back-to-back couplers in the same package, lets you monitor forward and reflected power. It also assures good directivity, flatness, and coupling accuracy. Typical applications include power sampling and measurement, amplifier leveling, VSWR monitoring, field control, and amplifier and load protection.