Planar version of Collinear Microstrip Patch Antenna

The paper presents a planar version of collinear microstrip patch antenna that exhibits further gain enhancement compared to collinear microstrip patch antenna due to the lateral extension of in-phase source current area of radiation element. The principle of operation is similar as in case of collinear wire antennas. The basic idea consists in the use of TM_0x mode with geometrical perturbation of radiation motif by inner slot(s) and lateral notches introduced in such a way that they eliminate radiation from even half current wavelengths. Detailed principle of an antenna operation explained via vector surface current distribution, determination of initial antenna dimensions and final optimization in planar simulator IE3D are presented. The prototype of the antenna operating in 2.4 GHz ISM band has been realized and measured.