BD131 is a bidirectional detector intended for simultaneous sampling of incident and reflected waves in high-power 2450 MHz industrial applications using an WR430 (R22) rectangular waveguide. The bidirectional detector combines the following components:

• 4-port directional coupler (70-dB coupling)
• Attenuators
• Tunnel diode detectors

The detector delivers well-scaled DC voltages proportional to power of the waves propagating in forward and reverse directions in the main waveguide. Standard maximum working powers P_max are 1 kW, 10 kW and 30 kW.

The use of tunnel diodes provides the bidirectional detector with improved temperature stability and fast pulse response.