WATTS ANTENNA COMPANY ...the tough site solution

Differential Global Positioning System (DGPS)
Pseudolite and Data Link Antenna
Prototype Model PS-5

The Model PS-5 is the first in a series of antennas intending to address the requirements of ground based antennas for differential global positions (DGPS) system precision approach and landing applications.  The intended application of this design is to provide a directive pattern for the differential data link and for radiation of "pseudolite" type signals to an aircraft on approach at a nominal decent angle.  Multipath signals below zero degrees elevation of the phase center have been reduced to minimize undesirable reflections from the earth's surface or sources located below the phase center in the airport environment.  The antenna can also be used to receive GPS signals from low elevation satellites with an enhanced signal-to-noise ration and reduced multipath effects.

The developmental antenna is the first produced for GPS applications by our corporation.  The radiating elements that comprise the array have been found, thus far, to be satisfactory in providing the needed radiation.  Cross polarization, a concern due to the diameter of the cavities at the operating frequency, has been measured as less than 20 dB.  The desired amplitude and phase distributions are achievable with the technique implemented.  The capacitive coupling probes, used to "tap" energy from the wave traveling in the coaxial line to the slot cavities, behave in a predictable fashion.  The application of the series feed slotted cable, common to all designs we produce will be expanded upon for the final design.  The radiating structure itself is considered very near production quality.

Contact Watts Antenna for current status of research and development on this project.