Vehicle Radar Substrate-Integrated Waveguide Shielding
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Solution Overview
Problem
Radar systems face challenges in efficiently routing high-frequency signals out of shielding areas without compromising shielding effectiveness, leading to signal attenuation and increased manufacturing complexity and cost due to the need for multi-layer systems and transitions between different substrate layers.
Innovation Solution
A radar system design featuring a printed circuit board with a conductor track surrounding the shielding area, connected to a waveguide with lateral delimiting walls and conductor surfaces, allowing for signal transmission without openings in the shielding housing, using a substrate-integrated waveguide to route signals efficiently and reduce interference.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If an opening is provided in the shielding housing to route the useful signal out of the shielding area, then the signal can be transmitted, but the shielding effectiveness is drastically degraded
Solution Approach 1:
The conductor track is segmented into two functional parts: a first section that forms the upper wall of the waveguide within the shielding area, and a second section that extends outside the shielding housing as a microstrip conductor. This segmentation allows the signal transmission path to be divided between the enclosed waveguide structure (maintaining shielding) and the external microstrip conductor (enabling signal output), thus resolving the contradiction between signal transmission and shielding effectiveness.
2Object-affected harmful factors
If a stripline line is used to route the useful signal under the shielding housing, then shielding effectiveness is maintained, but a multilayer system is required increasing manufacturing complexity
Solution Approach 1:
The waveguide structure is merged with the conductor track on the single substrate layer. The first section of the conductor track forms the upper wall of the waveguide, eliminating the need for separate stripline structures in additional substrate layers. This merging approach maintains shielding effectiveness through the enclosed waveguide structure while reducing manufacturing complexity by implementing everything on a single substrate layer.
3Ease of operation
If a transition from microstrip line to stripline line is made to route the signal under the shielding housing, then signal can be routed, but reflection losses and signal attenuation occur
Solution Approach 1:
The conductor track maintains homogeneity in its electromagnetic field characteristics by using a waveguide structure (first section) that is continuously connected to a microstrip conductor (second section) without requiring transitions between different transmission line types. The waveguide structure itself acts as the transmission medium, eliminating the need for microstrip-to-stripline transitions and their associated reflection losses and signal attenuation.
4Ease of operation
If through-contacts are used to route the useful signal from the uppermost layer to a lower substrate layer, then the signal can be routed under the shielding housing, but transition losses occur and manufacturing complexity increases
Solution Approach 1:
The signal transmission function is extracted from the need for through-contacts and multi-layer transitions. Instead of routing the signal through the substrate layer via through-contacts, the waveguide structure is formed directly on the uppermost substrate layer, with the first section of the conductor track forming the upper wall of the waveguide. This extraction eliminates transition losses associated with through-contacts and multi-layer transitions while maintaining the ability to route the signal under the shielding housing.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This design enables effective shielding of high-frequency signals within the radar system, reducing signal emission and interference, while simplifying manufacturing and reducing costs by eliminating the need for multi-layer systems and minimizing signal loss.
Implementation Method 1
at least one waveguide is arranged in the substrate layer, which waveguide has a laterally delimiting waveguide wall and an upper and a lower conductor surface
Implementation Method 2
a shielding housing covering the shielding area is electrically conductively connected to this conductor track
Data Source
Figure 1~2
Figure 3~4
AI summary
The invention relates to a vehicle radar system (2) for detecting the surroundings, having a circuit board (4), comprising a substrate layer (14) with an upper face (14a) and a lower face (14b), a conductor path (22) which is applied onto the upper face (14a), which comprises a shielding region (14b), and along which a shielding housing (6) that covers the shielding region (20) is connected to the conductor path (22) in an electrically conductive manner, and at least one waveguide (28) which is arranged in the substrate layer (14) and has a laterally delimiting waveguide wall (28c) and an upper and a lower waveguide surface (28a, 28b), the upper waveguide surface (28a) being a part of the conductor path (22).