Miniaturized 24 GHz FMCW Radar Leakage Mitigation With Synchronized Subtraction

Frequency-modulated continuous-wave (FMCW) radar sensors are widely used to measure range, velocity, and target status. As the range of applications for FMCW radar sensors expands, there is an increasing demand for smaller FMCW radar sensors suitable for use in confined spaces. To reduce the form factor of the FMCW radar sensor, the distance between the transmit (Tx) and receive (Rx) antennas is also reduced. This decrease in antenna separation increases the magnitude of the leakage signal transmitted from the Tx to the Rx antenna. However, the leakage signal makes it difficult for the FMCW radar sensor to detect the target by increasing the noise floor. In this article, we present an advanced method to mitigate the increased leakage signal power in the miniaturized FMCW radar sensor. We have fabricated a miniaturized homodyne FMCW radar with consistent leakage signal characteristics. We also propose a method to minimize the influence of the leakage signal by storing the leakage signal characteristics and using the stored data when operating the radar. The experimental results show significant leakage signal power reduction. This technique not only preserves the power of the received target signals but also improves the overall performance of compact FMCW radar sensors. The proposed method provides a basis for miniaturized radar sensors to contribute to various industries by providing an effective solution to the leakage signal problem of small radar technology.