Radar Sensor Crosstalk Reduction via Digital Interface Power Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Integrated radar sensors in vehicles face challenges with crosstalk from digital interfaces causing interfering sidebands in the radar signal, leading to excessive radiation beyond permitted limits due to the compact design of Monolithic Microwave Integrated Circuits (MMICs).
Innovation Solution
The radar sensor reduces output power when a predetermined level is detected on the digital interface's selection signal line, directly coupling this line to the control device to minimize interfering sidebands, thereby reducing the number of required pins and maintaining compliance with radiation limits.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a digital interface is integrated into the radar sensor for control and status reading, then the number of pins is reduced, but crosstalk from digital signals causes interfering sidebands that exceed radiation limits
Solution Approach 1:
The control device is configured to detect the predetermined level on the digital interface line before data transmission begins, and to reduce the output power in advance. This preliminary action prevents the harmful sidebands from being generated during the interface operation, allowing the digital interface to function without exceeding radiation limits.
2Object-generated harmful factors
If the output power is reduced to minimize interfering sidebands, then radiation limits are complied with, but the signal strength for radar detection may be compromised
Solution Approach 1:
The output power is dynamically adjusted based on the operational state of the digital interface. When the digital interface is active and generating crosstalk, the output power is reduced to minimize interfering sidebands. When the digital interface is inactive, the output power returns to normal levels to ensure optimal radar detection quality. This dynamic adjustment resolves the contradiction between minimizing harmful emissions and maintaining detection reliability.
Data Source
Figure 1
Figure 2
AI summary
The radar sensor has a transmission and reception device (11) for producing a radar signal at an adjustable output power (P), a control device (12) and an interface unit (13). The interface unit (13) and the control device (12) can be used to control the transmission and reception device (11) via a digital interface (23). The radar sensor is distinguished in that one of the lines of the interface (23) is connected to the control device (12), wherein the control device (12) is designed such that when a predetermined level is present on this line the output power (P) of the transmission and reception device (11) is lowered.