RD MIcrowaves designs and manufactures filter DIplexers/Cross Band Couplers using a unique suspended conductor in a stripline construction with mostly Air dielectric for low loss. The Diplexers may be used as Band combiners or Band dividers with typical isolation in the 50 dB region. VHF, Cellular, PCS, AWS, BRS bands may be combined in various combinations as shown on the PDF data sheet.