The WMPD03-2-18-S from Werbel Microwave is a 3 way, stripline power splitter that operates from 2 to 18 GHz. The divider has an insertion loss of less than 1.3 dB and an isolation of over 16 dB. It can handle up to 25 watts of power and has a good VSWR. The WMPD03-2-18-S is available in a module with SMA connectors.