3.4 Effect of Ground Plane

So far we have always accepted a ground as it is and then designed antennas around it. On the other hand, it has been demonstrated in Figure 3.8 that a ground isn't really a ground but one of the two radiation arms of an asymmetric dipole. Thus it should come as no surprise to know that the shape and size of a ground plane have prominent effects on the antenna built on it. Some published articles [30–33] have investigated the ground effect on a PIFA antenna or an IFA antenna. A straight wire monopole antenna is used here to study the effect. However, one should not count the dimension of a ground plane as a design freedom, because most of the time that dimension is solely decided by a product's industry design team. Some parameter studies presented here provide quantitative examples to help explain why some antennas work well on one phone but have problems when migrated to other p....