一种提高船舶导航雷达远距离探测能力的方法

船舶导航雷达接收机的中频窄带滤波器性能直接影响到雷达对远距离目标的探测能力。提出了构造一种提高船舶雷达远距离回波信号信噪比的“匹配滤波器”的方法。通过阻抗变换的方法设计高Q窄带中频滤波器，达到了2 MHz的通带宽度，小于3 dB的带内插损以及较高的矩形系数等设计目标。将滤波器运用于实际的船舶导航雷达接收机中，有效提高了雷达的探测距离。设计的窄带滤波器还有体积小、结构简单、制作方便、成本低等特点。

A method for improving the remote detecting capability of marine navigation radar

The performance of IF narrow-band filter in marine navigation radar receiver directly affects the remote target detecting capability of the radar. In this paper, a method for constructing a matched filter which can improve the remote target echo SNR of marine navigation radar is presented. A high Q narrow-band IF filter is designed based on the method of impedance transformation and achieves the expected goals: 2 MHz band-pass width, less than 3 dB insert loss in the pass band and sharper sharp-factor. Then the filter is used in an actual marine navigation radar receiver and the detection range of the radar is effectively improved. The filter also has the following advantages: small size, simple structure, convenient manufacture and low cost.