Directing at the demand of multi-mode, high gain at low elevation and high front-to-back ratio, a multi-mode conical PQHA (printed quadrifilar helical antenna) for GNSS (global navigation satellite systems) applications is proposed in this paper. A working band covering all the navigation frequencies is achieved by attaching a parasitic arm and an open stub, within which the axial ratio is less than 3dB. Meanwhile, an EBG (electromagnetic band-gap structure) reflector is introduced to reduce the antenna's backward radiation without a large rise in profile. This antenna is about 45% the size a typical cylindrical quadrifilar helical antenna is.