Design of Impulse Ground Penetrating Radar Signal Source Based on Power Synthesis

In the impulse ground penetrating radar system, bipolar signals have advantages over unipolar signals, such as wide bandwidth, high antenna radiation efficiency, and high detection accuracy. However, there are currently difficulties in bipolar signal generating. To solve these issues, this paper proposes a method for generating bipolar pulse signals using two unipolar pulse sources with different polarities, and using power synthesizer to put them together to be a bipolar signal. This method connects avalanche transistors in series to significantly increase the amplitude of the output pulse signal. For the generation of independent positive and negative polarity signals, an RF transformer is used to convert them through different electrical connection. Finally, after the delay controlling of two signals, a power synthesizer is used to combine them into a bipolar signal. This paper analyzes the relationship between the detection accuracy of ground penetrating radar and the signal source, verifies the feasibility of the synthesized signal through simulation analysis, and designs and implements a complete circuit board. In field experiments, the reliability of this signal source was verified, and it exhibited high detection accuracy.