Heterodyne architecture has been frequently chosen to resolve the problem of dc offset in frequency modulated continuous wave (FMCW) radar. However, heterodyne FMCW radars use different local oscillators, resulting in uncorrelated phase noise (UPN) in beat signals. Therefore, the inherent leakage signal in the heterodyne FMCW radar also has UPN and raises the noise floor in the power spectrum. In this letter, we propose a strategic decision method for parameter values in the heterodyne FMCW radar to achieve a low noise floor over the middle‐long range. In addition, we experimentally discover the relation between the UPN and the processing gain for the first time. Based on this relation, we devise an exact formula for the degree of improvement achieved due to the proposed strategic decision method. Experimental results confirm the devised formula and show that the proposed method significantly reduces the noise floor over the middle‐long range.

中文翻译：

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确定中远程低底噪的调频连续波雷达参数值的策略性方法

经常选择外差架构来解决调频连续波（FMCW）雷达中的直流偏移问题。但是，外差FMCW雷达使用不同的本地振荡器，从而导致拍信号中的相位噪声（UPN）不相关。因此，外差FMCW雷达中的固有泄漏信号也具有UPN并提高了功率谱中的本底噪声。在这封信中，我们为外差式FMCW雷达中的参数值提出了一种战略决策方法，以在中长距离范围内实现低本底噪声。此外，我们首次通过实验发现了UPN与处理增益之间的关系。基于这种关系，我们为提出的战略决策方法设计了改进程度的精确公式。