Cascading Radar LO Combining for Faster Chirps and Lower Phase Noise
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Solution Overview
Problem
MIMO radar systems are large, complex, and expensive due to their increased complexity, and traditional cascading radar systems are limited by settling and resetting times of a single LO signal, restricting fast-chirp waveforms and waveform diversity.
Innovation Solution
A scalable cascading radar system combines LO signals from multiple transceivers to generate a common oscillator signal, reducing settling and resetting times, enabling faster chirps and diverse waveforms.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a single primary LO signal is used in traditional cascading radar systems, then device complexity is reduced, but settling time and resetting time increase, limiting chirp rate and waveform diversity
Solution Approach 1:
The patent segments the single LO signal source into multiple independent LO signals from different transceivers. Each transceiver generates its own LO signal, eliminating the bottleneck of a single primary LO signal and reducing settling/resetting time constraints on chirp rate.
Solution Approach 2:
The patent combines multiple LO signals from different transceivers to create a composite LO signal that drives all transceivers. This merging approach maintains synchronization while eliminating the settling time limitations of a single primary LO signal.
2Loss of time
If multiple independent LO signals are used in each transceiver, then settling time and resetting time are reduced, but device complexity and cost increase
Solution Approach 1:
Each transceiver is designed to serve dual functions: it generates its own LO signal for rapid chirp transitions while also contributing its LO signal to the composite signal that drives all other transceivers. This multi-functionality resolves the complexity issue.
Solution Approach 2:
Each transceiver serves itself by generating its own LO signal, eliminating dependence on a primary transceiver. Simultaneously, each transceiver contributes to serving others by providing its LO signal to the composite signal distribution network.
3Stability of the object's composition
If a single primary transceiver generates the LO signal, then system synchronization is maintained, but waveform diversity and range resolution are limited
Solution Approach 1:
Different transceivers generate LO signals with different local characteristics (frequencies, modulation patterns). These local quality differences enable waveform diversity while the composite signal structure maintains overall synchronization.
Solution Approach 2:
The composite LO signal is formed by combining multiple LO signals with different characteristics, analogous to composite materials. This composite signal provides both synchronization (from the combined structure) and waveform diversity (from the individual signal characteristics).
4Device complexity
If the LO signal is shared among multiple transceivers, then device complexity is minimized, but chirp rate and Doppler coverage are restricted
Solution Approach 1:
The patent segments the LO signal generation function across multiple transceivers, allowing each to operate independently with rapid chirp transitions. This segmentation enables high chirp rates without the settling time constraints of a shared primary LO signal.
Solution Approach 2:
Each transceiver prepares its LO signal in advance without waiting for the primary transceiver to reset, enabling continuous high-rate chirp transmission. The preliminary generation of LO signals by multiple transceivers eliminates the bottleneck in chirp rate.
Data Source
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AI summary
The techniques of this disclosure describe a scalable cascading automotive radar system that generates a common oscillator signal enabling consecutive chirps to be output more quickly and precisely than any previous cascading automotive radar system, thereby reducing phase noise and improving performance. The scalable cascading automotive radar system combines a respective LO signal output from at least two primary transceivers to distribute the combined signals as a common oscillator signal to be input to all the transceivers of the radar system. Thus, settling time and resetting times that otherwise occur between chirps generated by other automotive radar systems are reduced because the common oscillator signal is no longer constrained to a single LO signal from a single primary transceiver.