ECHO Microwave's substrate diplexers integrate two filter channels into a single module, enabling efficient frequency separation or combining through one port. Built with Suspended Substrate Stripline technology, these diplexers achieve high isolation between channels, low insertion loss, and wide passband performance that conventional microstrip designs cannot match at higher frequencies. The precision CNC-milled cavity structure ensures repeatable performance and excellent temperature stability across the 1 GHz to 50 GHz operating range. Thin Film diplexer options are available from 6 GHz to 40 GHz for applications requiring compact SMT integration and volume manufacturability. Our substrate diplexers serve complex RF front-end architectures in military radar, airborne communication systems, satellite ground terminals, and electronic warfare platforms where multi-band operation and efficient frequency channelization are critical system requirements.