Simulation of electromagnetic properties is helping designers with antenna placement according to M Bandinelli of Siemens.
Modern vehicles are a significant challenge in terms of electromagnetic performance due to the very high levels of connectivity requirements both within the vehicle and also externally as part of vehicle to vehicle (V2V) and vehicle to infrastructure (V2x) communication requirements.
Whilst individual sub-assemblies and components are subjected to rigorous EMC testing protocols, the “whole vehicle” performance can still nonetheless be compromised. To reduce the risk of EMC and performance problems, antenna positioning and the avoidance of RFI coupling is important and difficult to achieve.
In a blog post for Siemens, M Bandinelli explains that it is critical for designers and engineers to find the ideal locations for antennas while also considering all the constraints and complexities related to electromagnetic interference. These growing complexities put pressure on developers to maintain performance amid time-to-market and budget constraints. With this in mind, an approach that relies on trial-and-error is too expensive, too time-consuming and no longer acceptable.
According to Bandinelli, automotive antennas operate in a complex environment and have to account for that environment in their design. They also have their own requirements such as shaped pattern, size, weight, installation constraints and regulations that need to be considered.
The antenna must work as part of an overall system with infotainment and other passenger comfort applications, operational vehicle sensors for advanced driver assist systems (ADAS) and other applications, all of which must functionally operate in all conditions.
In this respect, the field radiated by an antenna may cause electromagnetic interference with other co-installed antenna-based systems. The power radiated by a transmitting antenna may couple to a receiving antenna thus causing a desensitisation effect on the receiver. This runs the risk of potentially malfunctioning. Such electromagnetic interference risks must be controlled at design level.
With trial-and-error and chance being unacceptable design approaches, one alternative is the use of simulation software to assist in the design. This can help engineers to understand how electromagnetic performance can potentially impact and interfere with product performance.
For example, electrical motors, sensors and antennas are more prevalent. These components play a bigger role in the development process and must be part of electromagnetic simulation, which essentially means “viewing the invisible,” such as visualizing E-H field, currents, charge, voltages and energy/power distribution all along the 3D space, according to Bandinelli.
Progress in simulation technology has enabled a comprehensive digital twin to be produced, which can provide valid support to address design issues in an effective and efficient way. Measurements are then used to tune the digital twin and to verify the performance of the final antenna and platform configuration.
The comprehensive digital twin could also help simulate the exact 3D reality, allow designers and engineers to explore the design space and find trade-offs both at the antenna level and installation level, including minimising interaction with surrounding structures and interference with co-installed antennas and systems.
Just like simulation technology applied in other disciplines, electromagnetic simulation can be used for multiple purposes like analysis, diagnostics and certification support.
Simulation also enables faster prototyping and more efficient exploration of the design configuration in the early phases when no hardware is available. The software can be used to assess the effect of the ageing and modifications to the electromagnetic environment as well as the impact of the physical environment.
Without simulation, vehicles would have to be tested on 11 billion of miles of road — an unrealistic and impossible task. Simulation is helping reduce the process from months down to days. That’s why developers are increasingly using digital twin and simulation to test and validate antenna systems.