Angular Resolution Enhancement of the MIMO Radar by Using the 2D Nested Array Method

Subject Areas : Renewable energy

Rasoul Dehghani ¹ , Rouhollah Aghajani ²

1 - Department of Electrical Engineering- Najafabad Branch, Islamic Azad University, Najafabad, Iran
2 - Digital Processing and Machine Vision Research Center, Najafabad Branch, Islamic Azad University, Najafabad, Iran

Received: 2019-12-06 Accepted : 2020-06-12 Published : 2020-10-22

Keywords: Resolution enhancement, MIMO radar, virtual array, nested array,

Abstract :

In phased array systems, increasing the array length and consequently increasing the number of antenna elements are needed to improve spatial resolution. It can be addressed by MIMO radars using orthogonal signals from multiple transmitters and using the virtual array. Virtual element's locations are derived from the convolution of the physical elements of the transmitter and receiver. To understand the functionality of MIMO radars, virtual array has been introduced. As the virtual array be larger, the radar angle resolution increase. Increasing the degree of freedom of the virtual array is highly dependent on the array of transmitter and receiver elements placement. The Nested Array which is one of the well-known methods in alignment of MIMO radar array elements, is investigated. In this article, the new nested array is examined and implemented in one dimension. The very innovative idea of this article is to use the new 2D nested array. A multi-step approach for implementing two-dimensional arrays using a new nested array for a MIMO radar is presented which can be generalized to any other structure with different number of elements. Finally, the advantages of the proposed method in terms of angular bandwidth of the main radar are presented. The results show that the proposed method is much more efficient than the other methods. The comparative results presented at the end of this article shows that the half-power beam width of the proposed method is approximately 0.3 degrees while this value for the nested method is more than 2 degrees.

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