Dual-Frequency Radar Antenna Layout for Accurate Object Detection
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Solution Overview
Problem
Conventional radar antennas face challenges in increasing measurement accuracy without escalating production costs, size, weight, or power consumption, as methods like increasing aperture size or carrier frequency lead to higher costs.
Innovation Solution
A radar antenna design with two sets of antenna elements, one for a first carrier frequency and another for a higher second carrier frequency, where the distances between elements are bounded by half the wavelength of the first frequency, allowing for dual-frequency operation with suppressed side lobes and enhanced accuracy.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the number of antenna elements is increased to improve measurement accuracy, then measurement accuracy is improved, but production costs increase linearly
Solution Approach 1:
The antenna array is segmented into two distinct sets of antenna elements operating at different carrier frequencies. The first set operates at a first carrier frequency with spacing of at least half its wavelength, while the second set operates at a second carrier frequency (higher than the first) with the same minimum spacing constraint. This segmentation allows each set to be optimized independently, reducing the total number of elements needed while maintaining measurement accuracy.
Solution Approach 2:
The invention changes the operational parameters by using two different carrier frequencies instead of a single frequency. The first carrier frequency and second carrier frequency are both used to transmit radio signals, with the second being higher than the first. This parameter change enables the system to achieve higher measurement accuracy through frequency diversity without proportionally increasing the number of antenna elements.
2Measurement precision
If the carrier frequency is increased to improve measurement accuracy, then measurement accuracy is improved, but the number of transmit/receive modules per area increases
Solution Approach 1:
The antenna elements are segmented into two sets with different spacing requirements based on their operating frequencies. Both sets use the same minimum spacing (half wavelength of the first carrier frequency), which is less restrictive than using half wavelength of the higher second carrier frequency. This allows the system to operate at the higher second carrier frequency for improved accuracy without requiring denser element spacing, thus avoiding increased module density.
3Measurement precision
If antenna elements are spaced at half wavelength of the second carrier frequency to improve accuracy, then measurement accuracy is improved, but grating lobes appear in the antenna gain
Solution Approach 1:
The invention changes the spacing parameter from being based on the second carrier frequency wavelength to being based on the first carrier frequency wavelength. By spacing the antenna elements at at least half the wavelength of the first (lower) carrier frequency, the system maintains proper spacing for the higher second carrier frequency operation, preventing grating lobes while still achieving the desired measurement accuracy through the higher frequency's narrower main lobe.
Data Source
AI summary
A radar antenna comprises a first set of antenna elements, configured to transmit or receive radio signals at a first carrier frequency, and a distinct second set of antenna elements, configured to transmit or receive radio signals at a second carrier frequency which is higher than the first carrier frequency. A first distance between any two antenna elements of the first set and a second distance between any two antenna elements of the second set are both bounded below by one half of a wavelength corresponding to the first carrier frequency.