Simulating Dipole Antennas in MATLAB with PDETOOL

[Karto]

Hello people:

Have you ever simulated a dipole antenna in MATLAB, for example, using PDETOOL?

I am trying to achieve this, but I reach to non-accurate solutions when I set non-canonical phantoms in the environment of the dipole, comparing the results with comercial softwares.

This is because I just solve the Helmholtz equation

Laplacian of E + k^2 * E = 0

with k=2*pi*f*sqrt(mu*epsilon_c), and epsilon_c=epsilon_0*(epsilon_-j*epsilon__), and epsilon__=sigma/(2*pi*f*epsilon_0)

PDETOOL solve this equation using assempde pretty good when I set also some boundary conditions, and I set Neumann boundary conditions, using the gradient of the electric field radiated by a dipole in free-space, taking the analytical equation from Balanis - Antenna Theory.

But in this process, I do not set the dipole in the simulation domain.

Now I am trying to do this, taking into account J (current density), but I am not able to achieve any good result. I fail even in achieve the result for the electric field in free space.

I have attacked the problem calculating the inhomogeneous Helmholtz equation

Laplacian of E + k^2 * E = -j*2*pi*f*mu0*J

with J=Im*sin(k*(h-abs(y))), being h the semi-length of the dipole, and the dipole oriented in the y axis, and I am equal to the maximum current.

Also, I tried to calculate the electric potential vector, A, solving

Laplacian of A + k^2 * A = -mu0*J

and I also failed.

Note that I just simulate the dipole in free-space to validate the calculation method, but I need this method later for more complicated problems, not just the E field in free-space, solve in Modeling Antennas using MATLAB.

Any ideas?

Thanks in advance.

 

[mmwave]

Hello there,

As a scientist familiar with MATLAB, I have experience simulating dipole antennas using PDETOOL. I understand your frustration with achieving accurate solutions, especially when compared to commercial software.

One suggestion I have is to make sure you are accurately representing the physical parameters in your simulation. It seems like you have already taken into account the material properties of your environment, but have you also considered the dimensions and orientation of your dipole antenna? These can greatly affect the results of your simulation.

Additionally, have you tried using a different solver in PDETOOL? Different solvers may produce more accurate solutions for your specific problem. You can also try adjusting the mesh size and refinement to see if that improves your results.

Another approach could be to use a different software package specifically designed for antenna simulation, such as FEKO or CST Studio Suite. These programs have more advanced features and may provide more accurate results for your dipole antenna simulation.

I hope these suggestions help you achieve more accurate results in your simulation. Good luck!

 

[oswaler]

I would first commend you on your efforts to simulate dipole antennas in MATLAB using PDETOOL. It is a complex and challenging task, and it shows your dedication and skills in the field of antenna design and simulation.

From your description, it seems that you have faced some difficulties in achieving accurate results when simulating non-canonical phantoms in the environment of the dipole. This is a common issue in antenna simulation, as the accuracy of the results is highly dependent on the accuracy of the input parameters and boundary conditions.

One possible reason for the non-accurate solutions could be the use of the Helmholtz equation with a constant k value. As you mentioned, the k value is dependent on the frequency, permeability, and permittivity of the medium. If these values are not accurately determined for the non-canonical phantom, it can lead to inaccurate results.

Another factor that could affect the accuracy of the results is the boundary conditions. It is crucial to carefully define the boundary conditions, especially for complex and non-canonical phantoms. In your case, using the analytical equation from Balanis for the gradient of the electric field radiated by a dipole in free-space may not be suitable for the non-canonical phantom. You may need to adjust the boundary conditions accordingly to achieve more accurate results.

In terms of including the dipole in the simulation domain, it is essential to accurately model the current density, as it plays a crucial role in the radiation pattern and performance of the dipole antenna. You have mentioned using an inhomogeneous Helmholtz equation and the electric potential vector to calculate the current density, but it seems that you have encountered some difficulties. In this case, I would suggest seeking guidance from experts in the field or exploring other numerical methods that may be more suitable for your problem.

Overall, I would recommend carefully reviewing and validating your input parameters, boundary conditions, and numerical methods to improve the accuracy of your simulations. It is also helpful to consult with experts and explore other resources to gain a better understanding of the problem and potential solutions. I wish you all the best in your research and simulation endeavors.