tailieunhanh - Báo cáo hóa học: "Research Article Application of Frequency Diversity to Suppress Grating Lobes in Coherent MIMO Radar with Separated Subapertures"

Tuyển tập báo cáo các nghiên cứu khoa học quốc tế ngành hóa học dành cho các bạn yêu hóa học tham khảo đề tài: Research Article Application of Frequency Diversity to Suppress Grating Lobes in Coherent MIMO Radar with Separated Subapertures | Hindawi Publishing Corporation EURASIP Journal on Advances in Signal Processing Volume 2009 Article ID 481792 10 pages doi 2009 481792 Research Article Application of Frequency Diversity to Suppress Grating Lobes in Coherent MIMO Radar with Separated Subapertures Long Zhuang and Xingzhao Liu Department of Electronic Engineering Shanghai Jiao Tong University Shanghai 200240 China Correspondence should be addressed to Xingzhao Liu xzhliu@ Received 5 June 2008 Revised 27 December 2008 Accepted 1 May 2009 Recommended by Ioannis Psaromiligkos A method based on frequency diversity to suppress grating lobes in coherent MIMO radar with separated subapertures is proposed. By transmitting orthogonal waveforms from M separated subapertures or subarrays M receiving beams can be formed at the receiving end with the same mainlobe direction. However grating lobes would change to different positions if the frequencies of the radiated waveforms are incremented by a frequency offset Af from subarray to subarray. Coherently combining the M beams can suppress or average grating lobes to a low level. We show that the resultant transmit-receive beampattern is composed of the range-dependent transmitting beam and the combined receiving beam. It is demonstrated that the range-dependent transmitting beam can also be frequency offset-dependent. Precisely directing the transmitting beam to a target with a known range and a known angle can be achieved by properly selecting a set of Af. The suppression effects of different schemes of selecting Af are evaluated and studied by simulation. Copyright 2009 L. Zhuang and X. Liu. This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use distribution and reproduction in any medium provided the original work is properly cited. 1. Introduction Unlike a traditional phased-array radar system which can only transmit scaled versions of a single waveform a multi-input .