Summary
International Symposium on Antennas and Propagation
2010
Session Number:3TC3
Session:
Number:3TC3-5
DOA Estimation Using Subarray Dividing and Interpolated ESPRIT Algorithm for Multi-circle Conical Conformal Array
Tengda Liu, Feng Yang, Peng Yang, Jun Ouyang, Haijing Zhou,
pp.-
Publication Date:2010/11/23
Online ISSN:2188-5079
Summary:
Conformal antenna array, i.e., an array that conforms to an arbitrary surface, the application of that is much wider on future communication and defense [1].By contrast with ordinary arrays, adaptive conformal antenna array has some remarkable advantages, for instance, does not affect the aerodynamic characteristics of aerocraft, expanding the scanning range, increasing the effective aperture, high gain, overcoming the effects of platform, reducing RCS, and so on. But at the same time, due to the special conformal arrays and complex electromagnetic identities, there are a number of difficulties when the conformal array is used on wide range DOA estimation. Firstly, conformal array has the ‘‘shadow effect’’ because of the metallic carrier, which means for an incident wave from a special angle, some of the antenna elements can not receive the signal. Secondly, the radiation pattern of antenna element cannot be regarded as omni-directional since the platform behaves as a metallic ground. Therefore, for a conformal array, the elements’ radiation patterns are always directional. Thirdly, the classical spectrum estimation cannot be used to the whole array, when several elements do not work. Most high resolution DOA estimation algorithms, such as MUSIC-based [2] and ESPRIT-based [3] algorithms, require the array’s steering vector is complete (i.e. all the elements can receive the signal) and the radiation pattern of antenna elements are omni-directional. These algorithms cannot use to conformal array directly because of the array cannot satisfy above assumptions. Subarray dividing technique given by [4] can solve above problems efficiently, while complexity of the spectral searching in which is too high to fit for real-time applications. ESPRIT algorithm is a search-free DOA estimation algorithm, which exhibits lower computation and storage requirements than MUSIC algorithm by using a displacement invariant array. Though phase mode based ESPRIT algorithm can be applied to uniform circular array while classical ESPRIT algorithm can only be applied to uniform linear array, it cannot be used to conformal array, because of that the periodic excitation condition will be destroyed due to the incomplete steering vector [5]. In this paper, subarray dividing and interpolated ESPRIT-based methods are combined together for DOA estimation on conical conformal array. Simulation results exhibit the efficiency and accuracy of this method.