Abstract
After four decades of research, the Quadrifilar Helix Antenna (QHA) has become extremely popular for satellites and ground terminal applications. Formed from big wires during its inception, it has come a long way now to be tiny enough to fit in hand held terminals. It has a very effective performance capability suitable for several purposes. Antennas for modem day satellites and ground terminals not only need to be efficient in their performance but also need to be as small as possible. This report introduces the Printed Quadrifilar Helix Antenna (PQHA) for Satellite communications and Global Navigation and Satellite Systems, discusses its performance parameters along with current and past researches. A novel method of reducing the size of the antenna by incorporating a meandering technique with variable pitch angle is presented. The new antenna was built by taking as a reference conventional PQHA and has been named the Meandered Variable Pitch Angle Printed Quadrifilar Helix Antenna (MVPQHA). By using the technique of meandering and using variable pitch angle, the size of the antenna can be reduced by over fifty percent. The report also presents the technique of combining folded and meandered segments, along with an integrated feed network, which are conformal to the antenna structure. An integrated antenna is an attractive option for decreasing the overall size of the antenna. The report also presents a brief introduction on the kind of research that will be carried out in the future and the kind of improvement that can be made on existing Quadrifilar Helix Antennas.