Direction Of Arrival Estimation Based On Miniaturized Vivaldi Antenna Array

With the development of communication technology,more and more broadband signals are used in radar,communication,detection and other fields.Because Vivaldi antenna has the advantages of high gain,ultra-wideband,low return loss,high front-to-back ratio,low cross-polarization and easy processing,it is suitable for broadband signal receiving antenna.Direction of arrival（DOA）estimation is an indispensable technology for locating space emitters,so it is of great significance to study the direction of arrival estimation based on miniaturized Vivaldi antenna array.The main research contents and innovations of this thesis are as follows:（1）A new design method of miniaturization and high gain of Vivaldi antenna is proposed.The miniaturization of the antenna is realized by extending the current path by slotting technology,and the high gain of the antenna is realized by asymmetric design and loading lens technology.The test results show that the size of the new Vivaldi antenna is 0.37×0.26λ_OL,the operating frequency band is 0.47GHz-12GHz,and the gain is 1d Bi-11d Bi.Compared with the classical Vivaldi antenna,the size of the new Vivaldi antenna proposed in this paper is reduced by 34%,and the gain is improved by 0.9d Bi.Compared with the classical Vivaldi antenna array,the new Vivaldi antenna array effectively improves the mutual coupling between the array elements.（2）Simulation and analysis of RSS and TCT broadband signal direction of reach estimation algorithms.The effects of different signal sources,SNR,bandwidth,sampling fast beats and frequency points on the performance of the algorithm are simulated and analyzed.The results show that the DOA estimation performance of TCT algorithm is better than that of RSS algorithm.When the source bandwidth is 200MHz,the RMSE of RSS algorithm is 1.7 times that of TCT algorithm.Compared with RSS algorithm,TCT algorithm has better estimation accuracy under different SNR.At low SNR,the RMS error of TCT algorithm is about 1.07°lower than that of RSS algorithm.When the Angle of the incident signal is>20°,the estimation accuracy of the TCT algorithm is higher than that of the RSS algorithm,and the RMSE of the TCT algorithm decreases by about 30%when the frequency number increases by 1 times.（3）An integrated electromagnetic simulation system of antenna array and algorithm performance is built to verify the performance of wideband signal DOA estimation algorithm.Based on the proposed miniaturized Vivaldi antenna array,the performance of the wideband signal DOA estimation algorithm is verified by electromagnetic simulation under the condition of changing the type of incident source,source bandwidth,signal-to-noise ratio,sampling snapshot and frequency points.The results show that the electromagnetic simulation results are consistent with the theoretical analysis,and the TCT algorithm is more suitable for the DOA estimation of wideband signals than the RSS algorithm;the estimation accuracy of the TCT algorithm is higher than that of the RSS algorithm under different SNR;when the incident signal angle>20°,the estimation accuracy of the TCT algorithm is higher than that of the RSS algorithm under different source snapshots and frequency points,and the root mean square error of the TCT algorithm decreases more significantly with the increase of the number of frequency points.