Low intermodulation directional couplers are widely used in microwave communications as directional power distribution devices. With the continuous upgrading of communication networks, the working frequency in the field of communication continues to expand, which has higher requirements for the bandwidth of directional couplers. Our directional coupler has a frequency range of 0.4~13GHz, low insertion loss, high isolation, and a coupling degree of 10~30dB optional, the main form of connector SMA,N,7/16.