Feeder Width Tuning for Millimeter Wave Radar Side Lobes
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing millimeter wave radar array antennas face challenges in achieving a side lobe level lower than -13.2 dB without increasing material costs and requiring high precision processes, especially at high frequencies where implementing resistors or ground vias is difficult.
Innovation Solution
A series-fed microstrip patch array antenna design that adjusts the width of the feeder to secure the side lobe level without changing the radiator, eliminating the need for resistors or ground vias at the end terminal, and maintaining the same radiator shape for ease of design and manufacturing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If the radiant quantity of unit elements is adjusted to secure a side lobe level lower than -13.2 dB, then the side lobe level is improved, but the device complexity and manufacturing precision requirements increase due to the need for resistors or ground vias
Solution Approach 1:
The patent changes the width parameter of the feeder (microstrip line) to control the radiant quantity of each unit element. By varying the feeder width, the characteristic impedance changes, which directly controls the power distribution to each patch element, thereby achieving the desired side lobe level without requiring additional resistors or ground vias.
Solution Approach 2:
The patent divides the feeder into multiple sections with different widths, where each section corresponds to a different unit element. This segmentation allows independent control of power distribution to each element while maintaining a simple series-fed structure without requiring complex matching networks or additional components.
2Object-affected harmful factors
If resistors or ground vias are implemented to adjust radiant quantity, then the side lobe level is improved, but the ease of manufacture deteriorates due to high precision process requirements and difficulty at millimeter frequency band
Solution Approach 1:
The patent uses feeder width as a manufacturable parameter that can be easily controlled in PCB fabrication processes. Unlike resistors or via placements which require high precision alignment and additional manufacturing steps, feeder width can be directly controlled during the copper etching process, making it suitable for mass production at millimeter wave frequencies.
3Object-affected harmful factors
If the radiant quantity of unit elements is adjusted using conventional methods, then the side lobe level is improved, but the material cost increases due to additional resistors and ground structures
Solution Approach 1:
The patent achieves radiant quantity control through geometric parameter adjustment (feeder width) of existing PCB structures rather than adding additional components like resistors. This approach uses the same copper trace material already present in the PCB, eliminating the need for expensive surface mount resistors and additional ground via structures, thereby reducing material costs.
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 approach allows for a lower side lobe level without redesigning radiators, simplifying the manufacturing process and reducing material costs, while maintaining consistent radiating characteristics for polarization requirements.
Implementation Method 1
a first microstrip line which feeds the adjacent second patch to the first patch
Implementation Method 2
a plurality of patches arranged in an array and each patch having both ends open
Data Source
Figure 1~2
Figure 3
Figure 4
AI summary
The present invention suggest a patch array antenna which secures a side lobe level by changing a width of a feeder without changing a radiator and a radar signal transmitting and receiving apparatus including the same. The present invention provides a patch array antenna, including: a first unit element which includes a first patch which creates a predetermined radiation pattern and first feeders which are formed at both sides of the first patch and have the same width; and a second unit element is adjacent to the first unit element and includes a second patch which creates a radiation pattern and second feeders which are formed at both sides of the second patch and have the same width in which the width of the second feeders is different from the width of the first feeders.