An application-specific 20-dB coupler has been developed by Response Microwave for use in Long-Term-Evolution (LTE) fourth-generation (4G) cellular distribution systems. The coupler operates from 800 to 5800 MHz with typical insertion loss of 0.3 dB and minimum directivity of 23 dB. The coupling flatness is within 1 dB of the 20-dB value and the maximum VSWR is 1.15:1. The rugged coupler can handle input power levels as high as 50 W CW and is equipped with SMA female connectors. It is supplied in a compact housing measuring 3.9 x 1.5 x 1.02 in. and can operate at temperatures from -35 to +80C.