Design Of Transceiver Antenna For Time Domain Logging And Imaging Radar

Time domain logging imaging radar antennas have been used in more and more ground exploration projects.Because of their higher resolution,radars can work in very complex geological environments and have a wider detection range,so people will come The more energy is devoted to the time domain logging imaging radar antenna.This article integrates the actual needs of the project and the design requirements of the time domain logging imaging radar antenna.Dipole omnidirectional transmitting antenna,ferrite directional receiving antenna and cylindrical conformal monopole directional receiving antenna are designed respectively.This article first describes the topic background and significance of time-domain logging imaging radar research,the development history of time-domain logging imaging radar and the current research status at home and abroad,and introduces several radar antenna detection methods.Then it briefly introduces the technical principles of timedomain logging radar and some basic electromagnetic theories,such as the basic equations of electromagnetic field,the transmission characteristics of electromagnetic waves,and the characteristic parameters of time-domain antennas.Several basic analysis methods of antennas are explained.Then the time-domain is introduced.The basic principles of antenna design and common loading methods of antennas.Finally,three transceiver antennas are designed,as follows:A resistance-loaded double-cone improved dipole omni-directional transmitting antenna is designed.Different from the traditional cylindrical dipole antenna,this design adopts the form of a patch antenna and uses the Wu-King loading method to load the antenna with resistance.The antenna size is 160mm×56mm×4mm,the dielectric plate material is FR4,and CST2018 is used to complete the simulation and optimization of the dipole antenna in this software,and it is concluded that the changes of various parameters have an effect on the performance of the omnidirectional dipole transmitting antenna.Finally,the omnidirectional transmitting dipole antenna was processed and tested,and the actual test results of the antenna were not much different from the simulation results;secondly,a ferrite directional receiving antenna was designed,using the dipole antenna as a prototype in a metal back cavity Loaded ferrite material to achieve directivity,analyzed the radiation performance of the antenna in different environments,analyzed and optimized it in the CST simulation software,broadened the bandwidth of the directional receiving antenna,and greatly improved the radiation efficiency of the directional receiving antenna.At the same time,the tailing oscillation of the antenna timedomain waveform is reduced;finally,in order to conform to the borehole structure of the antenna and realize the miniaturization of the radar system,a cylindrical sector-shaped monopole directional receiving antenna is designed,and the antenna structure is compact and adopted Lumped method for resistance and capacitance loading,diameter 40 mm,height 26 mm,fan-shaped monopole is wrapped with dielectric FR4,the signal fed by the antenna is a first-order Gaussian pulse with a peak-to-peak value of 300 ps,in the 0.5GHz-2GHz frequency band,S11 is less than-10,The front-to-back ratio of the antenna timedomain waveform is greater than 5:1,indicating that the antenna has good directivity and the working bandwidth can be expanded at low frequencies.After the simulation optimization design is completed,the antenna is processed and tested,and the antenna physical test results are not much different from the simulation results.Meet the design requirements of radar receiving antenna.