However, in practical situation, the BTM antenna is usually mounted horizontally, i.e., [alpha] = 0 while the BMH h remains unchanged.
Besides, from Figure 9(b) we can see that the ER value is directly related to the shape of curve [A.sub.ev] (x'), while [A.sub.ev] (x') is determined by the BMH as expressed in Equation (24).
Figure 12 shows that the BMH greatly affects curve [A.sub.ev] (x').
Hereby, based on the longitudinally mounting and according to Equation (24) and Equation (27), we calculate the ER value for each BMH varying from 0.26 m to 0.5 m with the step of 0.001 m and the results are shown in Figure 13.
Figure 13 shows that the ER value is a unimodal function of BMH, and the optimum ER value is [R.sup.*.sub.ld] = 0.793 m at the BMH of [h.sup.*.sub.ld] = 0.381 m.
To verify the proposed optimization scheme, we will have to change the balise mounting style and adjust the BMH, which is inconvenient in practice.
Under the conditions when the balise is mounted transversally and longitudinally, respectively, we measure the start-operation position and the end-operation position of the balise when the BMH is h = 0.26 m, 0.30 m, 0.33 m, 0.37m, 0.42 m, 0.5 m, etc., and calculate the ER values according to Equation (27), the results are represented by the dashed lines in Figures 17(a) and 17(b), respectively.
The performance optimization based on the tele-powering signal transmission described above is mainly from perspectives of the balise mounting style and the BMH, yet Equation (12) shows that the transmission process is also affected by the pitch angle of the BTM antenna [alpha].
Based on the test plan in Figure 16 and the transversal mounting of the balise, we measure the ER values according to Equation (35) under different pitch angle conditions of [alpha] = 30[degrees], 45[degrees], 60[degrees], and 90[degrees], respectively when the BMH is h = 0.26m, 0.30m, 0.33 m, 0.37m, 0.49 m and 0.62 m, etc., the measured and the corresponding theoretical results are represented by the dashed and solid lines in Figure 19, respectively.