Injection-Locked Phased-Array Doppler Radar for Multi-Target Detection
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Solution Overview
Problem
Conventional Doppler radar systems can only detect a single moving target, limiting their effectiveness in multi-target scenarios and requiring an internal source signal, which increases power consumption and may interfere with wireless communication devices.
Innovation Solution
A phased-array Doppler radar system employing an injection-locking technique that uses an external radio signal and a receive antenna array to demodulate and process multiple reflected signals, enabling the detection of multiple targets or parts of a target through digital beamforming without an internal source signal.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If an internal source signal is used in Doppler radar, then the radar can detect targets, but power consumption increases and interference with wireless communication devices occurs
Solution Approach 1:
The patent uses an external radio signal from a wireless communication device as an intermediary to replace the internal source signal. This external signal serves as the carrier wave for Doppler radar operations, eliminating the need for a dedicated internal oscillator and reducing power consumption while avoiding interference with communication devices.
Solution Approach 2:
The patent makes the external radio signal from the wireless communication device serve multiple functions: it acts as both the communication signal and the radar carrier wave. This multi-functionality eliminates the need for separate signal sources, reducing overall system power consumption while maintaining target detection capability.
2Reliability
If an internal source signal is used in Doppler radar, then the radar can detect targets, but interference with wireless communication devices occurs
Solution Approach 1:
The patent uses an external radio signal from a wireless communication device as an intermediary to replace the internal source signal. This external signal serves as the carrier wave for Doppler radar operations, eliminating the need for a dedicated internal oscillator and reducing power consumption while avoiding interference with communication devices.
3Measurement precision
If conventional Doppler radar is used, then a single target can be detected, but multiple targets cannot be distinguished
Solution Approach 1:
The patent segments the received signal into multiple channels, each corresponding to a different spatial direction or target region. By dividing the signal processing into separate pathways, the system can independently analyze and distinguish multiple targets simultaneously while maintaining the detection precision of individual targets.
Solution Approach 2:
The patent introduces spatial dimensionality to the detection system by using multiple receive antennas arranged in an array. This allows the system to distinguish targets not only by their Doppler shift but also by their spatial position, enabling multi-target detection while preserving single-target detection accuracy through spatial filtering.
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 system achieves high detection performance for multiple targets or parts of a target, reducing power consumption and avoiding interference with wireless communication devices, while facilitating a joint radar and communication system.
Implementation Method 1
The ILO is electrically connected to the two-way splitter to receive and be injected with the other part of the reference signal, and thus generates an injection-locked signal
Implementation Method 2
Doppler radar is a device that detects a target's movement based on the Doppler effect. The movement of the target with respect to the Doppler radar varies the phase difference between the radar signal transmitted to the target and the echo signal reflected from the target.
Data Source
AI summary
A phased-array Doppler radar includes a two-way splitter, a transmit antenna, a receive antenna array, an ILO, a demodulation unit and a digital signal processing unit. A reference signal is split by the two-way splitter to the transmit antenna for transmission to targets and the ILO for injection locking. Signals reflected by the targets are received by the receive antenna array as received signals. An injection-locked signal generated by the ILO and the received signals received by the receive antenna array are delivered to the demodulation unit. The received signals are demodulated into baseband I/Q signals by the demodulation unit that uses the injection-locked signal as a local oscillator signal. The baseband I/Q signals are processed by the digital signal processing unit to obtain a digital beamforming pattern.