BC211 is a dual directional coupler intended for simultaneous sampling of both incident and reflected waves in high-power 900 MHz industrial applications using an WR975 (R9) rectangular waveguide.

Two coupling factor options are available: -60 dB for maximal input power 10 kW in the waveguide, and -70 dB for maximal input power 100 kW.

The coupler is fixed to the parent waveguide using eight M3 or similar-diameter screws after machining of appropriate holes in the broad waveguide wall. The parent waveguide (standard or customized) can optionally be part of delivery. The standard length is 300 mm.