Slot-coupled circular microstrip antenna having a symmetric radiation pattern

The author presents the analysis and design of a circular microstrip antenna coupled through an annular slot to a coaxial line. The annular slot is concentric with the circular patch. This method of coupling yields a symmetric radiation pattern and a linear polarization that is different from that of the conventionally fed microstrip antennas. The structure is analyzed using the finite-difference time-domain (FDTD) technique in cylindrical coordinates. Numerical results are presented.<
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