Quadrifilar helical antennae with four separate ports and providing a reduction in height are described. The QHA includes four conductive helical traces wound about a common longitudinal antenna axis. The conductive helical traces are configured for transmitting or receiving at a selected frequency band. Each conductive helical trace is connected to a respective port of the antenna via a respective launch line. The QHA also includes at least one conductive component insulated from the conductive helical traces and superimposed over the conductive helical traces. The at least one conductive component is configured to provide impedance matching at the frequency band.