STMicroelectronics has diplexers to address a wide range of frequencies. Each diplexer has been built to suit custom specs (frequency band, insertion loss requirements, out-of-band rejection and isolation). Datasheets for each P/N are available at http://www.st.com/stonline/stappl/productcatalog/app?page=productSelector under EMI filtering and signal conditioning. If there is interest in a custom diplexer, feel free to contact ST’s customer support.