Dual or Multi-band Microstrip Antennas by Using Disturbing Pathes

The purpose of this paper is to employ the technique of disturbing patches in micro strip cavity to design an antenna with dual or multiple-band operation. The design concept first uses a single metal to disturb the originally uniform distributed electric field in antenna cavity, so that two different modes can be produced without changing radiation too much. Further, the shape of the disturbing metal is modified to adjust frequency separation, the number of disturbing is used to increase a third mode for operation. The simulation, and experiment both prove that an antenna with a single disturbing patch can operate at dual band. The one with triangular disturbing can adjust frequency separation effectively. The two disturbing patches are placed vertically, three acceptable modes can be achieved. The structure in design is simple and coplanar, it is easy to fabricate by PCB technology.