Numerical and computational analysis of radiation characteristics of dielectric loaded helical antenna

Abstract

In this paper, a full-wave analytical theory has been proposed based on the field theory approach and numerically solved for computing radiation properties of the dielectric-loaded helical antenna (DLHA). First, the dispersion equation is analytically derived from the source-free Maxwell equation subject to necessary boundary conditions. Then radiation characteristics of DLHA are derived using the field theory approach. The effect of polarization current arising due to dielectric on radiation properties is addressed for the first time in the case of DLHA. All the numerical analysis is carried out in MATLAB. To further validate the results, computation analysis is carried out using CST Microwave Studio Software. From the result, it was observed that when the circumference of the antenna (C) is comparable to the wavelength (λ) corresponding to operating frequency then the wave propagates axially through the helical wire in the axial direction and is radiated in the end-fire direction whereas when the circumference is not equal to the wavelength then the wave gets radiated in the normal direction and attenuated in the axial direction. Also, the impedance bandwidth of the antenna is increased from 2.5% to 52.9% and the gain is increased from 8.35 dB to 11.5 dB due to teflon loading. Finally, the antenna prototype is fabricated, measured, and compared with the numerical and computational results. A close agreement between the analytical, computational, and measurement results are found.

Omnidirectional circularly polarized collinear helical antenna using self‐canceling sections

“…Generally, there are two kinds of radiation modes of helical antennas with three‐dimensional structure: axial mode and normal mode radiation. An axial‐mode helix with a circumference of around λ has a unidirectional circularly polarized beam with a wide impedance bandwidth, medium gain, and has been widely investigated and used in many wireless communication systems 4,5 . Compared to an axial‐mode helix, a normal‐mode helix has an omnidirectional radiation pattern and a very compact structure with a helix diameter of less than 0.18 λ .…”

“…An axialmode helix with a circumference of around λ has a unidirectional circularly polarized beam with a wide impedance bandwidth, medium gain, and has been widely investigated and used in many wireless communication systems. 4,5 Compared to an axial-mode helix, a normal-mode helix has an omnidirectional radiation pattern and a very compact structure with a helix diameter of less than 0.18λ. When operating in the circular polarization state, its height (total length along its axis) is in the order of a λ/2 helix.…”

Development of a new method for modeling a physical system in a rational expression

“…[1][2] On the other hand, simulation of physical structures using the full-wave simulators is commonly time-consuming, due to the complexity of them. 3 Moreover, to study of a complex structure in the presence of nonlinear components, a hybrid combination of frequency and time domain are necessary. 4 Hence, a helpful intuitive concept for understanding the properties of a complicated structures is its equivalent circuit model.…”

“…Most of the time, analysis of many practical problems in engineering is very difficult based on the first principle 1–2 . On the other hand, simulation of physical structures using the full‐wave simulators is commonly time‐consuming, due to the complexity of them 3 . Moreover, to study of a complex structure in the presence of nonlinear components, a hybrid combination of frequency and time domain are necessary 4 .…”