QUADRIFILAR HELICAL ANTENNA AND FEED NETWORK

摘要

A QHA antenna and feed network for a GPS receiver has a helical antenna with a pair of baluns mounted on a PCB at right angles to a central axis of the antenna. Each balun can provide or combine two RF signals 180° phase shifted relative to each to each other. Each balun having a ground plane (32), a first conductive path (33) electrically connected to the ground plane, a second conductive path (31) substantially parallel to the first conductive path, a third conductive path (34) electrically connected to the first conductive path and electrically connected to the ground plane, a fourth conductive path (35) substantially parallel to the third conductive path and connected to the ground plane. The second (31) and third (34) conductive paths being electrically connected to each other, so that a signal input to the second conductive path results in a substantially similar signal being provided at the first (33) and fourth (35) conductive paths, but being 180° shifted in phase.