Research On Miniaturization Of The Receive Array In Hf Radar

Recently HF ground wave radar has been increasingly concerned and studied, which has superiority in ship and low-flying target detection over the horizon. The large area of the antenna array limits the application of the HF Radar, so it is imperative to research the miniaturization of radar receive array in high frequency band. This paper studies the circular super directive array which is used as the array element of the receive array of HF Radar. It optimizes the array super directive gain subject to side lobe constrains, and then calculates the minimum of the array efficiency to guarantee the dominance of the external noise. MUSIC algorithm is also used for spatial spectrum analysis of the receive array. Besides, the paper gives the mutual coupling calibration algorithm based on mutual coupling matrix for circular array, and this weakens the mutual coupling effect. The reasonable compact super directive circular antenna array which conforms to directivity and resolution demands is designed.Firstly, this paper introduces the elementary knowledge related to the antenna array and its minimization. The mathematical model of ULA (uniform linear array) and UCA (uniform circular array) are given. Then it analyzes the pattern of the UCA, the practical application of super directive antenna in HF radar and the fundamental principles of the MUSIC algorithm.In the second place, the synthesis method of the circular super directive antenna is presented considering the maximum of the directivity of the circular antenna array. To reduce the side lobe effect of the circular array, another synthesis way which optimizes the array directive subject to side lobe constrains is given. It is realized by the iterative method of suppress the side lobes. The simulation results of both synthesis methods are presented. Besides, the efficiency of circular array which guarantees the dominance of the external noise in the HF receive system is give. These facts taken together, the suitable circular super directive antenna array is designed.What's more, the mutual coupling effects and its calibration method for circular array have been studied. The mutual coupling calibration algorithm which is based on the mutual coupling matrix modeling and subspace orthogonality is given under white Gaussian noise. Under the background of colored Gaussian noise, improved mutual coupling calibration, which uses the four order cumulant, is investigated for the circular array. At last, the simulation results validate the performance both the algorithms.Last but not least, the Chebyshev linear array is formed using the designed circular super directive array as array element. Considering the demands of directivity, resolution probability and the band width, the compact receive antenna array, which realizes the minimization of HF receive array, is achieved.