Disclosed is a signal splitter that includes a coupled transmission line element coupled between two output ports of the signal splitter. The coupled transmission line element is used to lower the isolation between the two output ports for a particular frequency band. The coupled transmission line element includes a first and a second elongate electrical conductor. The first and the second elongate electrical conductor first ends are coupled to the signal transmission path that connects the two output ports. The first and the second elongate electrical conductor second ends are un-terminated. The first elongate electrical conductor and the second elongate electrical conductor are not shorted together, and the first elongate electrical conductor and the second elongate electrical conductor are electrostatically coupled, such as by twisting them together into a helix.