Aperture coupled microstrip slot antenna

Aperture coupled microstrip slot antenna couples the patch antenna with microstripline through an aperture. To improve the radiation pattern, there are three techniques -First using reflector plate, second using cavity and third by adjustment of the phase angle using the movement of the patch antenna on the slot i.e. by adjusting the SWR distribution. The third technique improves the radiation pattern without using reflector plate or cavity and it increases the F/B ratio. One effective way to increase the impedance bandwidth is to change the feed shape and the slot shape. The shape of coupling aperture has a great effect on the strength of coupling between the feed line and the patch. Mainly thin rectangular shape of the slot is used in aperture coupled microstrip slot antenna. If, it is chosen a suitable combination of the shapes of feed and slot and tuned perfectly, it gives an optimum impedance bandwidth with a stable radiation pattern.