**5. Conclusion**

188 Numerical Simulation – From Theory to Industry

to obtain the preset input resistance.

line with a wave resistance of 50 Ohm.

approximately.

It follows from the results of simulation that it is not reasonable to make Mр>4 in the antenna. For each M value, it is necessary to optimise the sizes of elements of arrays in order

Fig. 43а shows the version of a linear array with a quasi-isotropic directional pattern in the E-plane. Such a pattern can be obtained, if to bend all the arrays along the Z axis at an angle

 =35-40°. It is possible to ensure the preset input resistance by choosing the sizes of elements. Fig. 43b,c shows the directional patterns and the values of the parameters of G (Gain), NR (nonuniformity of a directional pattern in the E-plane), R, X, values of VSWR in a

, the gain is 3 dB more

In a linear array consisting of arrays with a lateral length *L* 0,5

**Figure 44.** Loop antenna with quasi-isotropic directional pattern in E-plane

(a) (b) (c)

The simulation results, given in this chapter, complete the information about dipole and loop antennas that is available in the literature, and can be used to choice a type of an antenna according to specified requirements and after estimating its main characteristics. Numerical simulation of an antenna can be done with the use of the formulas given in the description of a mathematical model. When using a program developed on the basis of these formulas, it is necessary to carry out research into the convergence of the results of calculation. The most sensitive parametre of the antenna in relation to the number of segments of division of conductors (M) is the input resistance. When using impulse functions as the basis and weight ones, it is possible to be oriented towards the following recommendations: the ratio of a segment length to a conductor diameter *L Ao* / 2 0,8-1,2; the number of segments at a wavelength: 80-200.

In some cases, the results given in the graphs can be used directly with the use of electrodynamic scaling.

We express aur gratitude to D.Moskalev and V.Kizimenko for the useful discussion of the results described in this chapter.
