Patent ID: 7138949

Claim:
A fourteen inch diameter GPS microstrip antenna comprising: (a) a first dielectric layer; (b) a plurality of square shaped antenna elements mounted on an upper surface of said first dielectric layer, said antenna elements being equally spaced apart, aligned with one another and fabricated from copper, said antenna elements being adapted to receive an RF carrier signal containing GPS (Global Positioning System) data at a frequency of approximately 1.575 GHz; (c) a solid copper plate mounted on the upper surface of said first dielectric layer, said solid copper plate including a dielectric gap formed around in the periphery of each of said antenna elements separating each of said antenna elements from said solid copper plate; (d) 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 antenna feed network having a plurality of branch transmission lines branching out from said main transmission line wherein one of said plurality of branch transmission lines is connected to each of said plurality of antenna elements, said antenna feed network being configured to drive each of said antenna elements with equal amplitude and equal phase RF signals resulting in a circular polarization and an omni-directional radiation pattern being generated by said plurality of antenna elements of said GPS microstrip antenna; (e) a copper cross hatch pattern mounted on the bottom surface of said first dielectric layer in proximity to said antenna feed network; (f) a band stop filter integrally formed within the main transmission line of said antenna feed network, said band stop filter isolating GPS radio frequency signals from TM band radio frequency signals over a frequency range from about 2 GHz to about 7 GHz; (g) a diode limiter connected to said main transmission line in proximity to said signal output for said antenna feed network; (h) an amplifier connected to said main transmission line in proximity to said signal output for said antenna feed network, wherein said filter, said diode limiter, and said amplifier provide for a nominal 25 dB gain and a maximum noise figure of 1 dB for an amplifier bias of 3 volts at 20 milliamperes; and (i) a second dielectric layer positioned below said first dielectric layer in alignment with said first dielectric layer, said second dielectric layer having a solid copper ground plane affixed to a bottom surface of said second dielectric layer.