Compact Gps Antenna: Theory, Design, Fabrication and Measurements

Many applications in communications and radars require circular or dual linear polarization, and the flexibility afforded by microstrip antenna technology has led to a wide variety of designs and techniques to fill this need. In recent years, the demand for compact mobile telephone handsets has grown. Handsets with size of a pocket have begun appearing in the market and, as the demand for increased electronic mobility grows, the need for small handsets will most likely increase. A small antenna size is required as one of the important factors in portable mobile communication systems. Various techniques have been explored to develop small size antenna. One of these techniques is achieved by using shorting wall. For a rectangular MPA, its resonance frequency is on the order of half-wave length. The length of the antenna is reduced by a factor of two if the half-wave patch is short-circuited to the ground at the zero potential planes. The result is a resonance rectangular patch with length of order ?/4, called a quarter-wave patch or Shorted