Automotive Radar Sensor Design and Placement

 

Design requirements for 24 GHz and 77 GHz automotive radar sensors are becoming more stringent as consumers increase demand for applications like blind spot detection (BSD) and lane change assistance (LCA). In turn, the engineering departments at Tier 1 suppliers like Delphi, Autoliv, and Continental are advancing technology in order to win bids from OEMs like BMW, Audi, and Chrysler.

 

 

 

Types of Analysis

Remcom’s time-domain electromagnetic simulation software, XFdtd, is a proven tool that promotes the rapid development of automotive radar sensors. Using simulation, RF and Application Engineers are able to analyze the far-field radiation characteristics of their antenna which minimizes the number of prototypes built and tested in a lab. This applies to the following:

  • Designing the layout of the feeding structure and radiating elements on a multi-layer RF board.
  • Determining a matching radome while accounting for all the complexities in a full sensor model: RF board, radome, packaging, data connector, case, etc.
  • Finding or troubleshooting the placement of a sensor behind fascia.

 

Highlights

Having been validated against measurements, XF is the EM simulator of choice for analyzing these complex, high frequency sensors. The following capabilities aid the analysis:

  • Time-domain electric field animations show the root cause of parasitic coupling between radiators so it can be mitigated.
  • GPU acceleration enables a simulation time of 30 minutes for a fully detailed, 24 GHz, RF board with 188 parts.
  • XF's efficient implementation of the Finite-Difference Time-Domain (FDTD) method only requires 1.7 GB of RAM for the 24 GHz model.
  • Far-field radiation patterns quantify the effects of fascia curvature, mounting brackets, and paint color.
   

 

 

Additional Information

 

Benefits of Time-Domain Electromagnetic Simulation for Automotive Radar

This paper demonstrates how XF's time-domain EM simulation enables rapid development by allowing engineers to determine the performance of a fully detailed sensor model installed behind a piece of fascia. A 25 GHz sensor frames the discussion.

 

Introduction to FDTD EM Simulation for Automotive Radar

To meet the increasing accuracy needs of high performance automotive radar design work, the FDTD EM simulation method has emerged as a better solution than traditional FEM formulations. This paper introduces FDTD’s advantages for automotive radar circuit and systems level designers.

 

Application Example: Convex Lens at 77 GHz

A convex dielectric lens, designed for 77 GHz, is compared against a similar plano-convex lens using XF7.