RESEARCH AND DESIGN OF CIRCUIT FOR GENERATION OF TRANSMITTING SIGNAL FOR GROUND PENETRATING RADAR

Abstract

In Ground Penetrating Radars, ultra-short pulse modulated signals in the form of Gaussian pulses are often used as the transmission signal, and the pulse generator is one of the core components that determine the resolution of the surveyed object and the performance of the radar. In this paper, we analyze typical ultra-short pulse generation methods such as: step recovery diodes; tunnel diodes; avalanche transistors; photoconductor semiconductor switches and direct digital synthesizers DDS. From there, we propose a solution to design a pulse signal generation circuit for Ground Penetrating Radars, with the criteria of simplifying the circuit structure, ensuring the parameters and quality of the transmission signal. The test results on the prototype circuit obtained the output pulse signal with the following parameters: pulse width of 7.8 ns; pulse repetition frequency of 71.45 kHz; pulse amplitude over 40V with 10V power supply voltage. The generated pulse signal ensures target detection at depths up to 20 m with 0.5 m resolution. This solution demonstrates the possibility of adjusting the output pulse signal parameters with simple design and low cost.