LCP Patch Array Antenna Layout for Wider 77 GHz Radar Bandwidth
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing 77 GHz radar antennas using Rogers RO4835 substrates suffer from narrow bandwidth and signal interference due to parallel arrangement of patch antennas, leading to unstable performance under varying environmental conditions.
Innovation Solution
An array antenna design utilizing a liquid crystal polymer (LCP) substrate with patch array antennas connected in series and featuring concave slots on the radiating surface of the foremost patch antenna, along with a perpendicular arrangement of transmitting and receiving ends to reduce interference and improve impedance matching.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If Rogers RO4835 substrate is used for patch array antennas, then antenna structure can be formed, but absorption rate reaches 0.05% and cannot sustain severe environment challenges, leading to unstable performance
Solution Approach 1:
The patent changes the substrate material parameter from Rogers RO4835 to LCP (liquid crystal polymer), which has superior environmental stability with absorption rate below 0.03%. This material substitution resolves the contradiction by maintaining performance stability while reducing sensitivity to environmental variations such as temperature and humidity changes.
2Measurement precision
If patch array antennas are arranged in parallel to achieve beam forming characteristics, then directivity and beam transmission are improved, but signal interference occurs between transmitting and receiving antennas
Solution Approach 1:
The patent introduces asymmetry by adding concave slots to specific patch antennas in the array. This asymmetric modification creates frequency selectivity that allows the antenna system to distinguish between transmit and receive signals at different frequencies, thereby maintaining high directivity while reducing signal interference between transmitting and receiving elements.
3Device complexity
If conventional patch antenna design is used, then simple structure is achieved, but working bandwidth is excessively narrow
Solution Approach 1:
The patent applies local quality modification by adding concave slots to specific patch antennas rather than modifying the entire antenna uniformly. These localized concave features create additional resonant modes and expand the impedance matching bandwidth, achieving wider working bandwidth while maintaining the overall simplicity of the patch antenna structure.
Data Source
AI summary
An array antenna of a radar includes a liquid crystal polymer (LCP) substrate with antenna transceiver circuits embedded. A plurality of patch array antennas are disposed on the LCP substrate and connected to the antenna transceiver circuit. Each patch array antenna includes a plurality of patch antennas connected in series, and the foremost patch antenna has a concave slot on the radiating surface by each side of respective feed line. By use of a LCP substrate can ensure stable material characteristics in different environments. Compared with a single patch antenna, the gain may be improved by 6 dB by connecting four patch antennas in series. A concave slot is formed on a radiating surface of a patch antenna to optimize a feed impedance, thereby to improve a working bandwidth of the antenna to alleviate an excessively narrow bandwidth of a patch antenna.