Читать книгу Antenna and EM Modeling with MATLAB Antenna Toolbox - Sergey N. Makarov - Страница 27

Although impedances of many basic antenna types and geometries (dipoles, loops, patch antennas) are well documented (in particular, in Antenna Engineering Handbook, John L. Volakis, Ed., McGraw Hill, 2018, fifth edition), any particular antenna design heavily relies upon numerical electromagnetic modeling.

Let us compare the theoretical model for the dipole antenna impedance with a numerical model. The theoretical model is based on a cylindrical dipole (1.14). The modeling software used in this text is the Method of Moments software of the MATLAB^® Antenna Toolbox^™. This software has a library of antenna models that are parameterized to enable easy geometry setup and analysis. One such model is the dipole.

This model of the dipole in MATLAB will use the strip or blade approximation of the cylindrical dipole as discussed in [3]. We consider the same dipole as in Example 1.5, with the total length of 15 cm, and with the radius of 2 mm, and then compare its theoretical impedance model given by Eq. (1.14) with numerical simulations, in the band from 200 to 1200 MHz. As discussed above, the equivalent radius of the strip dipole of width t is a_eq = t/4.