Radar Radome Recess for Antenna Coupling Reduction
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Radar systems face noise interference due to mutual coupling between transmitting and receiving antennas caused by radomes, which reduces system performance and sensitivity, especially in wide-field-of-view applications like automotive corner radar sensors, and existing solutions like additional absorbers or band gap structures are costly or prone to manufacturing issues.
Innovation Solution
Incorporating a recess within the radome's inner surface to redirect and block multiply scattered radiation, thereby reducing coupling between the transmitting and receiving elements without the need for additional absorbers or band gap structures, while maintaining compact dimensions and standard printed circuit board usage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If a flat radome is used to protect antennas, then protection against environment is improved, but mutual coupling between transmitting and receiving antennas increases due to reflections at large incident angles
Solution Approach 1:
The radome surface is segmented by introducing a recess that divides the inner surface into different regions. This segmentation creates distinct reflection paths for electromagnetic waves, preventing direct coupling between transmitting and receiving antennas while maintaining environmental protection.
Solution Approach 2:
A recess is introduced into the radome structure, adding a third dimension to the otherwise flat surface. This dimensional change creates a non-planar surface that redirects electromagnetic reflections in different directions, reducing mutual coupling between antennas.
2Object-generated harmful factors
If additional absorbers are placed between transmitting and receiving paths to reduce coupling, then noise level is reduced, but system cost increases
Solution Approach 1:
The radome structure itself is modified to serve the dual function of environmental protection and coupling reduction. The recess in the radome automatically redirects reflections without requiring additional absorptive materials, making the system self-sufficient and cost-effective.
Solution Approach 2:
The coupling reduction function is extracted from separate components (absorbers) and integrated directly into the radome structure itself. This eliminates the need for additional components while achieving the same noise reduction effect.
3Object-generated harmful factors
If horizontal distance between transmitting and receiving antennas is increased to reduce coupling, then noise level is reduced, but entire dimensions of radar system increase
Solution Approach 1:
Instead of increasing horizontal separation distance, the solution uses a vertical dimension by introducing a recess into the radome. This redirects reflection paths in the vertical direction, achieving coupling reduction without increasing the horizontal footprint of the system.
Solution Approach 2:
The recess introduces a curved or non-planar surface geometry to the radome, which naturally redirects electromagnetic waves through geometric reflection. This curved surface approach achieves spatial separation of reflection paths without increasing overall system dimensions.
4Object-generated harmful factors
If reflectivity of flat radome is reduced for high incidence angles, then coupling is reduced, but protection performance deteriorates
Solution Approach 1:
The radome surface is segmented by the recess, creating different surface regions that handle different incident angles. The recess specifically addresses high incidence angle reflections while the rest of the radome surface maintains its protective function for other angles.
Solution Approach 2:
The recess is strategically positioned to affect only specific reflection paths from high incidence angles. This local modification to the radome surface quality allows selective control of reflections without compromising the overall protective function of the radome structure.
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
The recess effectively decouples the transmitting and receiving elements, reducing noise levels and enhancing sensitivity by redirecting multiply scattered radiation, achieving improved isolation without increasing system dimensions or costs.
Implementation Method 1
a significant part of radiation which is caused by multiple scattering effects of the radiation of the transmitting element is blocked or redirected
Implementation Method 2
The coupling is due to the energy originating from reflection at large incident angles on both sides of the radome and due to further multiple reflections at an antenna board
Data Source
Figure 1
Figure 2
Figure 3
AI summary
A radar system comprises a transmitting element adapted to transmit a radar signal, a receiving element adapted to receive a reflected signal of the radar signal being transmitted by the transmitting element, and a radome covering the transmitting element and the receiving element and having an inner surface and an outer surface. The inner surface of the radome faces the transmitting element and the receiving element. The radome comprises a recess being located at the inner surface.