Pseudo closed form solution for center fed monopole and dipole antenna

Abstract

The proposed approaches to deal with the antenna problems fall in two categories, the numerical solution and the analytical solution. Another technique to deal with the antenna problems is the equivalent TEM mode theory, introduced in 2002. This model considered the antenna to be an inner conductor of a fictitous open circuited lossy transmission line thus the propagation constant has to be complex with real part and imaginary part representing the attenuation constant α and the phase constant β respectively. However the values of the phase constant and the attenuation constant were tabulated and no closed form expressions or empirical formulas were provided and the procedure for extracting the model parameters was rather complicated and had no regular approach. These drawbacks were covered to a great extent in 2008, they provided a simple approach for extracting the model parameters in the case of center fed dipole antenna. The propagation constants were interpolated using the proper empirical formulas. However these empirical formulas were functions of the characteristic impedance Zo. The used approach was based on estimating the characteristic impedance Zo without showing it's effect on the results. These empirical formulas showed accurate results for the half wavelength antenna and all it's odd multiples, on the other hand they showed a significant deviation for the complete wavelength antenna and it's multiples. Moreover this model was not verified for other types of antennas. This paper verifies the model for the monopole antenna and the center fed dipole antenna with empirical formula for the characteristic impedance Zo to give accurate results for antennas with different electrical lengths.