1. Field of the Invention
The subject invention relates to antennas. Particularly, the subject invention relates to microstrip antennas for circular polarization applications.
2. Description of the Related Art
Antennas for receiving signals from a satellite, such as Satellite Digital Audio Radio Service (SDARS) signals, are well known in the art. These antennas are routinely carried on vehicles for use with the vehicle's radio receiver. Typically, these antennas are mounted on a metallic roof of the vehicle such that the roof acts as a ground plane for the antenna. Furthermore, these antennas often have a bulky appearance that is not aesthetically pleasing from the outside of the vehicle.
Many modern vehicles incorporate glass into their roof. The amount of glass used can range from a typical sunroof that provides glass over a small portion of the vehicle roof to a panoramic-style glass that spans the entire roof area of the vehicle. Unfortunately, the use of glass in vehicle roof structures reduces the amount of sheet metal that can be used as a ground plane for a satellite antenna. As such, typical satellite antennas suffer from lower performance when disposed on glass.
Therefore, there remains an opportunity for an antenna that may be integrated with glass, such as a glass roof of a vehicle, for receiving signals from a satellite.