Bowtie Antenna

This article illustrates that FEKO can be applied to the simulation of planar antennas with bowtie antennas as example.

Antenna on a dielectric halfspace

The first example is of a bowtie antenna that was simulated by placing the structure on a dielectric halfspace.  For the sake of validation against open literature the model is based on an antenna presented in [1] for the analysis of gain vs. angle on incidence on the antenna.  Figure 1 shows this antenna with the currents on it simulated at 94 GHz, while Figure 2 shows the comparison between the published data [1] and the result generated with FEKO.  The FEKO result is in excellent agreement with the result published by Compton [1].

Figure 1:  Currents on a bowtie antenna at 94 GHz

Figure 2:  Normalized gain vs incidence for bowtie antenna at 94 GHz
(a) Results published in [1] (b) Result computed with FEKO

Figure 3 presents an input impedance comparison of a bowtie antenna at 2 GHz, as the length of one half of the bowtie varies from 0.05 λ₀ to 0.5 λ₀.  The input impedance is presented on a Smith-chart with the length of the half bowtie labeling the plot points.  All impedance values were normalized to 152 Ω.

Figure 3:  Normalized impedance with varying length for bowtie antenna at 2 GHz
(a) Results published in [1] (b) Result computed with FEKO

Antenna raised above real ground

Leat [2] analyzed the same bowtie antenna configuration depicted in Figure 1 as it is raised over a real ground.  Figure 4 presents an input impedance comparison as the antenna is raised higher above ground.  Agreement is good across the entire frequency range, from 50 MHz to 500 MHz.

Figure 4:  Input impedance as a function of height above real ground
(a) Results published in [2] (b) Result computed with FEKO

References