48 Y.E. Ozcelik et al. Fig. 6.1 Monopole antenna structure [3] Table 6.1 Conductivity of the some common materials [4] Material Conductivity (S/m) Material Conductivity (S/m) Silver 6.30EC07 Zinc 1.70EC07 Copper 5.80EC07 Brass 1.00EC07 Gold 4.10EC07 Phosphor Bronze 1.00EC07 Aluminum 3.50EC07 Tin 9.00EC06 Tungsten 1.80EC07 Lead 5.00EC06 15 10 5 −5 −10 −15 0 0 5 10 15 20 Time (s) Acceleration (m/s2) 10−4 103 25 30 35 Fig. 6.2 Time history of mechanical shock [6] communication systems is broken down due to a mechanical shock, the whole system will be unable to function properly. For example, a printed circuit board (PCB), printed on the antenna structure, may be damaged due to exposure of a high level of mechanical shock, and as a result of this, the system becomes dysfunctional. Therefore, antenna structures must be designed to withstand mechanical shock types, which are explained briefly below, to ensure their reliability. Transportation and handling shock is received by electronic and mechanical systems used in military and civil applications as a result of transportation and human errors in handling of materials. For instance, while a military armored vehicle is running over a bump at unwary speed, all systems including antennas are exposed to mechanical shocks. Furthermore, ballistic shock is another type of mechanical shock containing high amplitude and high frequency content which is mainly caused by the impact of non-perforating mine blast, projectiles or ordnances on armored vehicle [7]. In addition to that
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