FMCW Radar Transmitter Circuit with Random Chirp Blanking
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Solution Overview
Problem
Radar sensors face challenges with high energy consumption and heat dissipation, as well as cross-talk interference, particularly in densely packed automotive applications using frequency-modulated continuous-wave (FMCW) radar systems.
Innovation Solution
A transmitter circuit for FMCW radar sensors that generates a frequency-modulated RF signal with randomly omitted chirp pulses based on a pseudo-random sequence, reducing energy consumption and heat generation while minimizing cross-talk through the use of a random number generator and controller circuit to enable and disable the RF oscillator.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If continuous chirp pulses are transmitted in FMCW radar, then measurement precision is maintained, but energy consumption and heat dissipation increase significantly
Solution Approach 1:
The patent applies periodic action by transmitting chirp pulses in a periodic sequence with regular time intervals rather than continuously. The RF oscillator is enabled and disabled in a periodic manner, creating a pulsed transmission pattern that reduces energy consumption while maintaining measurement capability through the periodic reception and processing of reflected signals.
Solution Approach 2:
The patent implements partial action by transmitting only a subset of chirp pulses that are sufficient for accurate measurement rather than the maximum possible number. By determining an optimal number of chirp pulses that achieves the required measurement precision, the system performs only the necessary portion of the transmission sequence, reducing energy consumption without sacrificing measurement accuracy.
2Area of stationary object
If multiple radar sensors operate in close vicinity, then coverage area is improved, but cross-talk interference between sensors increases
Solution Approach 1:
The patent applies dynamics by varying the time intervals between chirp pulse sequences of different radar sensors. Instead of all sensors transmitting at fixed regular intervals, each sensor dynamically adjusts its transmission timing, creating non-uniform time spacing that prevents synchronous interference and reduces cross-talk while maintaining comprehensive coverage area.
Solution Approach 2:
The patent uses periodic action with varying periods for different radar sensors. Each sensor transmits chirp pulses in periodic sequences, but the period duration is adjusted individually for each sensor. This creates a staggered periodic transmission pattern where sensors are not all transmitting simultaneously, reducing cross-talk interference while collectively covering the required area.
Data Source
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AI summary
A method for a radar transmitter is described herein. In accordance with one exemplary embodiment, the method includes generating an RF transmit signal composed of at least one sequence of sub-sequent chirp pulses, wherein pseudo-randomly selected chirp pulses are blanked, and radiating the RF transmit signal via at least one antenna as radar signal.