步进频率连续波探地雷达耦合信号的抑制

Cancellation of the Direct Coupling in a SFCW Ground Penetrating Radar

步进频率连续波是探地雷达常用波形之一,该体制雷达存在的一个严重问题是发射信号直接耦合到接收天线,降低接收机灵敏度,导致接收机前端饱和甚至损坏。针对步进频率连续波体制探地雷达,采用通过收发天线设计降低耦合信号,保证其不会导致接收系统饱和,再在中频数字域进行对消的耦合抑制方案,详细分析了其工程实现流程和应用条件,给出了某步进频率连续波合成孔径探地雷达耦合波对消前后的雷达图像,说明了耦合对消方法的有效性。该方法在某探地雷达中获得实际应用,工作稳定可靠。

Stepped frequency continuous wave is usually transmitted in ground penetrating radar（GPR）.One of the major problems encountered is the large leakage from the transmit signal to the receive antenna,which decreases the receiver sensitivity,saturates the receiver,and even damages the receiver.To cancel the leakage signal of SFCW ground penetrating radar,the transmit and receive antennas are properly placed to improve the T/R isolation,assuring that the receiver is not jammed.Then a digital intermediate frequency coupling cancellation scheme is adopted.The engineering application algorithm and the restrictions of the method are given.SFCW GPR images have been presented to demonstrate the effectiveness of the leakage signal suppression method.The coupling cancellation method works well with an ground penetrating radar.