Slot Cut Modified Triangular Shape Microstrip Antenna for Circular Polarization

Modified design of triangular microstrip antenna obtained by combining two triangular shape patches is discussed. The offset distance between two patches tunes the spacing between orthogonal mode frequencies of the patch which yields circular polarized response with axial ratio bandwidth of 5%. Further to realize compact configuration, slot cut design of offset triangular overlap patches is studied. The rectangular slot helps in tuning the spacing between offset triangular patches along with offset distance to yield circular polarization. The detailed parametric study for the effects of slot along with offset distance in circular polarized antenna is presented. The tuning of orthogonal frequencies is obtained at lower offset distance between two patches for slot cut antenna. The optimum axial ratio bandwidth of 70 MHz in 1500 MHz frequency band is obtained along with broadside gain of 7 dBi and VSWR Bandwidth of 747 MHz. In optimum case slot cut overlapped design offers 42% reduction in patch area.