distance d Ͼ 20 mm, the antenna effect could be negligible. It should also be noted that taking the effect of the human head into account is certainly justifiable and, depending on the operating frequency.Also from Figure 5, it is found that most of the investigated antenna shapes have acceptable SAR less than 1.6 W/Kg (IEEE standard). The best shapes are quad-band PIFA without and with fractal concept. Their SAR values equal 0.48 and 0.6 W/Kg, respectively. These values are much better than several mobile antennas in the market (such as Motorola V3688) with SAR of 1.91 W/Kg. Effect of the Human Head on the Antenna CharacteristicsIn this section, we summarize some of the results reported on the electrical characteristics for antennas in handheld devices. There may be a reduction in gain and change in the level of side lobes, as the antenna moves closer to the head. We can summarize these effects in the following points.1. The frequency is shifted down due to the presence of the human head. The maximum shift is 6%, but most of the antennas still operate in resonating band. This can be attributed to the coupling between the antennas and the human head. 2. The reflection coefficient of the antenna is increased, but the antenna is still matched for the most part. 3. The antenna-radiation efficiency is reduced due to the amount of the absorbed power in the human body. 4. The bandwidth is reduced by about 3% on average, but most antennas still operates with acceptable bandwidth. 5. The antenna directivity is reduced by about 4 dB on average. 6. The far-field radiation pattern is distorted. The front-to-back ratio is reduced. The pattern shape has some unpredictable changes, depending on the antenna position, orientation, and polarization directions. Figure 1. The rods or holes are placed to form a specifically shaped lattice (for example, square or triangular). These 2D structures need to be electrically small in their third dimension for application in the antenna. An EBG structure has several forbidden bands, but most applications use only the first one. To design a 2D EBG structure with a prefixed frequency band-stop, it is possible to consult an atlas of band diagrams [2], which are not available for every structure. Otherwise, the structure must be simulated with an appropriate software which requires a trial-and-error process to obtain the desired solution.In this work, we present a software that uses a genetic algorithm (GA) with a heating and cooling process to provide the design solution for a specific requirement and, if desired, includes constraints with regard to materials, dimensions, and so forth. This is especially interesting when a prefixed stop-band is needed and, in particular, if there are any kind of constraints in reference to the available materials or other design parameters [6]. This software has been developed in MATLAB. ANALYSIS METHODPreviously, to develop a program that includes an optimization process, it was necessary to create one's own MATLAB software that was able to analyze 2D diele...