*In a previous article, I mentioned about design & analysis of antenna using electromagnetic simulation and important aspects to be considered. In this article, I explain effect of a platform on radiation characteristics and how hybrid solving methods can help towards effective antenna placement.*

It has become routine for automotive OEMs to integrate different types of antennas in their vehicles. In recent years, many industry professionals have been focusing on implementing projects related to Internet of Things (IoT). There’s ever-growing demand for IoT integration for consumer electronics, vehicles and so on. Consequently, estimating actual performance of the antenna with any platform (vehicles, electronic devices and buildings) is becoming challenging!

In recent years, automotive industry is introducing Advanced Driver Assistance Systems (ADAS) for automating and enhancing the vehicle system and its safety. The growing interest for wireless connectivity relies more and more on integrated antenna solutions customized for optimal system performance, and any failure can cause the delay in a critical product launch. ANSYS provides the technology for the various solution techniques for simulating individual antenna to final placement for estimating various characteristics.

**Hybrid Solving Methods for Antenna Placement**

You can easily assess the effect of the platform on the performance of the antenna using Hybrid Solving Methods. You can apply traditional approaches such as the finite element method (FEM), Finite Difference Time Domain (FDTD) to problems of moderate electrical size. Significant computational resources are necessary for these numerical methods. Therefore, we will need to further extend the capability of FEM to the solution of electromagnetic radiation and scattering problems. These could involve disjoint obstacles such as reflector antenna systems, antennas mounted on large platforms, and antennas in the presence of radome structures. To achieve this, several methods such as method of moments (MoM), high frequency techniques such as Physical Optics (PO) and Shooting & Bouncing Rays (SBR+) have been hybridized with FEM.

Furthermore, the below schematic will allow you to select an appropriate solution technique based on the geometric & material complexity and electrical size of the problem that you wish to solve.

Hybrid Solving Methods provide the solution for

**Radiation Patterns**of the Antenna after mounting it on the proposed platform**Coupling between Antennas**placed on the platform.**Optimal Position**for an Antenna over given platform.**Faster Computation Times**

###### Finite Element Boundary Integral (FEBI) & SBR+

Among the several hybrid solving methods, I’ll focus on FEBI and SBR+ in this section. In both these methods, you simulate a part of the antenna with FEM. Then, you simulate the platform effects with either integral equations or high frequency techniques. To effectively calculate currents near the antenna, you need to analyze the antenna using the FEM and feed these results into FEBI or SBR+ methods.

In general, electrically large problems could be solved with FEBI technique & electrically larger problems can be solved with SBR+ technique. For a smaller problem scope, FEM will do the trick! Since both the hybrid methods are equally applicable for many problems, you’ll need to be aware of the subtle reasons for selecting the most appropriate method that is relevant to the platform. We can help you with this if you need any assistance!

The combined simulation with feed network analysis is also possible with the help of ANSYS Circuit Simulator. With this, you can interface field solver results with those from FEM-Hybrid Techniques.

###### Relevance to ADAS Applications

When we think about non-monitored driving, the ADAS system can handle all the situations: partial or full scenarios. Toyota President Aikido Toyoda recently said to ensure ADAS system safety, we need 8.8 billion miles of testing of autonomous vehicle design. This is not only expensive, but also impractical. ANSYS-Powered Simulations have a crucial role in ADAS because of availability of multiple software tools for different kinds of analysis and easy integration with others.

You can simulate Radar Antennas in Autonomous Vehicles with HFSS and conduct initial placement simulation with hybrid methods (FEBI or SBR+). We can simulate different driving scenarios that accounts for other vehicles, buildings, trees etc. by including detailed physics. This is possible by using HFSS SBR+. These virtual test results can be used to test & validate control algorithms and vehicle dynamics.

###### Summary

ANSYS Electromagnetic Simulation Software provide the necessary requisites to validate design and placement of the antennas for different applications. In addition, Hybrid Solving techniques provide for various benefits including faster computation times, optimal position studies among others.

Going a step further, you can extend these studies to ADAS applications by integrating results from ANSYS Electronics Simulation Software.

I hope the article was useful to you. If you wish, you can download a recent Webinar on Antenna Design and Placement using ANSYS Software. Of course, please feel free to reach out to me if you have any questions.