Simulation of a probe-fed notched patch antenna with a shorting post

Microstrip patch antennas have serious limitations in bandwidth and for many applications their resonant length of half a free space wavelength is too large. Recently, a probe-fed notched patch antenna was shown to provide a bandwidth in excess of 20% (see Chen, Z.N. and Chia, M.Y.W., Electron. Lett., vol.36, no.7, p.599-600, 2000). The antenna is a square patch with notches cut into two of the sides. The notches provide a reactive loading allowing the use of a thick substrate (/spl sim/0.08/spl lambda/) and induce a second resonance near the main patch resonance. This paper reports simulation results of a probe-fed notched square patch antenna with a shorting post. The antenna has an area that is 94% smaller than the area occupied by a square half wave patch and maintains a bandwidth of 13.2%. A parametric study on the size of the notch was done showing that, with the proper dimensions, this antenna can be made to operate over two frequency bands although both of these bands have a smaller bandwidth than the single band case.