Design, assembly and testing of a high gain LHCP helical antenna for reception of reflected GPS signals

This paper describes the design, assembly and fleld testing of a LHCP (Left Hand Circularly Polarized) high gain helical antenna. The antenna is to be utilized for the reception of re∞ected Global Positioning System (GPS) signals, which are correlated with the direct signals to form an image of the area of interest. Thus the antenna forms a constituent element of a remote imaging system. Owing to the low power of the re∞ected GPS signals the major design parameter was obviously high gain, while maintaining the polarization integrity of re∞ected GPS signals.