Ambiguous Doppler Radar Electronic Scanning
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Solution Overview
Problem
Existing radar systems face challenges in providing high angular resolution and reducing digital processing requirements while maintaining low complexity and cost, especially in high-speed moving platforms or rapidly changing scenes, due to limitations in mechanical scanning, electronic scanning, and beam formation methods.
Innovation Solution
The radar system employs an active antenna with an ambiguous electronic scanning configuration, using arrays of elementary transmission and reception antennas with different ambiguity periods to form focused radiating patterns within a limited field, allowing simultaneous formation of reception beams in ambiguous transmission directions, and utilizes Doppler filtering to reject residual ambiguity lobes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If mechanical scanning with narrow beam is used to achieve high angular resolution, then angular discrimination is improved, but refreshment time increases and reliability decreases
Solution Approach 1:
The patent replaces mechanical scanning with electronic beam steering using phased array technology. Multiple beams are formed simultaneously in different directions by electronically controlling the phase and amplitude of signals across array elements, eliminating mechanical moving parts and enabling instant beam switching for high refreshment rates while maintaining narrow beamwidth for angular discrimination.
Solution Approach 2:
The patent divides the observation field into multiple angular sectors and forms separate beams for each sector simultaneously. This segmentation allows parallel observation of different angular regions, achieving complete field coverage with high angular resolution without sequential scanning, thus reducing refreshment time.
2Adaptability or versatility
If electronic scanning with large number of phase-controlled elements is used to achieve wide angular coverage with good resolution, then angular field coverage and discrimination are improved, but device complexity and cost increase
Solution Approach 1:
The patent uses a single phased array that can form multiple beams simultaneously in different directions and frequencies. The same array elements serve multiple functions: transmitting and receiving, forming beams in different angular sectors, and operating across multiple frequency bands, thereby achieving wide angular coverage without proportionally increasing the number of elements.
Solution Approach 2:
The patent introduces frequency diversity as an additional dimension alongside spatial diversity. By operating multiple beams at different frequencies, the system achieves wide angular coverage and enhanced discrimination without simply adding more spatial elements, thus controlling device complexity while expanding operational versatility.
3Device complexity
If beam formation by computation with single wide-field antenna is used to reduce device complexity, then device complexity is reduced, but angular discrimination decreases and transmission power requirement increases
Solution Approach 1:
The patent replaces the single wide-field antenna with a phased array structure that enables electronic beam forming. This substitution maintains relatively simple physical structure while achieving high angular discrimination through phase-controlled signal processing across multiple elements, avoiding the need for high-power transmitters.
4Power
If MIMO with multiple transmission and reception channels is used to maintain modest elementary transmission power, then transmission power requirement is reduced, but processing load increases significantly
Solution Approach 1:
The patent combines multiple reception channels into a single integrated beam forming processor that simultaneously processes signals from all elements. By merging the processing functions and using coherent integration across channels, the system maintains modest transmission power while reducing the overall processing load compared to independent MIMO channel processing.
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 configuration enables efficient coverage of a wide angular field with reduced processing load and cost, allowing for virtually instantaneous image generation and improved refreshment time, even in high-speed applications, while maintaining moderate power consumption and using standard electronic components.
Implementation Method 1
a focusing of the transmission antenna is carried out in a different direction from transmission pulse to pulse with a formation of at least one reception beam in the direction of focusing of the transmission for each pulse emitted
Implementation Method 2
Other solutions, of the type 'with multiple inputs and outputs' referred to as MIMO (acronym for Multiple Input Multiple Output)... the radar processing must be applied to all of these N×M channels
Data Source
AI summary
A Doppler radar with ambiguous electronic scanning, using an active antenna comprising an array of elementary transmission antennas and an array of elementary reception antennas with the same angular opening. The arrays have the same radiation plane. The transmission array is ambiguous with a number of ambiguous lobes within said angular opening of said elementary antennas greater than or equal to 2. The reception array comprises at least one ambiguous lobe within said angular opening. The arrays are arranged so that the product of the transmission and reception radiating patterns only produces a single main beam within the field defined by said angular opening. The coverage of said angular field by said radar obtainable by:forming at the transmission antenna radiating patterns that are focused within a field limited to the transmission ambiguity field;simultaneously forming several reception radiating patterns focused at reception in the ambiguous transmission directions.