QuinStar Technology’s QJC series of compact precision crossguide directional couplers cover the frequency range of 18 to 170 GHz in nine waveguide bands. Three-and four-port configurations are available for standard models with midband nominal coupling values of 20, 30 and 40 dB. Other coupling values are available as custom products. Crossguide couplers are ideal devices for sampling or inserting RF energy in a waveguide transmission line without affecting the transmitting signal. Typical applications include frequency monitoring, power sampling and built-in testing. The crossguide type of directional coupler has the advantage of lower insertion loss, smaller size and lower cost when compared to broadwall directional couplers. QuinStar can provide custom configurations and application-specific interfaces to suit unique needs.