Patent ID: 6943737

Claim:
A GPS (Global Positioning System) microstrip antenna mounted on a projectile comprising: (a) a first rectangular shaped dielectric layer; (b) a plurality of square shaped antenna elements mounted on an upper surface of said first dielectric layer, said antenna elements being aligned with one another and fabricated from copper, each of said antenna elements being positioned at an angle of approximately forty five degrees on said first dielectric layer, said antenna elements being adapted to receive GPS (Global Positioning System) data at a frequency of approximately 1.575 GHz; (c) an antenna feed network mounted on a bottom surface of said first dielectric layer, said antenna feed network having a main transmission line connected to a signal output for said GPS microstrip antenna, said feed network having a plurality of branch transmission lines connected to said main transmission line and each of said antenna elements, each of said branch transmission lines including a pair of probes positioned perpendicular to one another underneath one antenna element of said plurality of antenna elements, one of said pair of probes for each of said branch transmission lines having a length substantially greater than the other of said pair of probes for each of said branch transmission lines to provide for a ninety degree relative phase shift between RF signals transmitted through said pair of probes for each of said pair of branch transmission lines resulting in a circular polarization and an omni-directional radiation pattern being generated by said antenna elements of said GPS microstrip antenna; (d) a pair of identical filters integrally formed within said main transmission line, said pair of identical filters isolating GPS radio frequency signals from TM band signals over a frequency range from about 2 GHz to about 7 GHz; (e) a diode limiter connected to said main transmission line in proximity to said signal output for said feed network; and (f) an amplifier connected to said main transmission line in proximity to said signal output for said feed network, said diode limiter and said amplifier providing for an overall gain of approximately 27 decibels.