DocumentCode :
54290
Title :
All-Pass Filter-Based 2-D IIR Filter-Enhanced Beamformers for AESA Receivers
Author :
Wijenayake, Chamith ; Madanayake, A. ; Belostotski, Leonid ; Yongsheng Xu ; Bruton, Len
Author_Institution :
Univ. of Moratuwa, Moratuwa, Sri Lanka
Volume :
61
Issue :
5
fYear :
2014
fDate :
May-14
Firstpage :
1331
Lastpage :
1342
Abstract :
An active electronically scanned array (AESA) beamforming method that provides enhanced selectivity (interference rejection) for the same number of antennas compared to conventional delay-and-sum (DAS) beamforming is proposed. Conventional DAS 2-D transfer function is modified by introducing complex pole-manifolds based on recently proposed 2-D infinite impulse response (IIR) beam filters, at guaranteed stability. A continuous-time domain signal flow graph is proposed based on first order all-pass filters that eliminate the need of transmission line-based delays used in conventional DAS beamformers. Improved interference rejection is verified using closed-form signal processing models. For an array of 64 antennas, with desired signal direction of arrival (DOA) 10 ° and interference DOA -60° from array broadside, the proposed scheme shows an improvement in the signal-to-interference ratio (SIR) around 7 dB for the same number of antennas, compared to DAS beamforming. The improvement in interference rejection is observed for both uniform and non-uniform aperture weights in terms of side lobe performance. A feasibility study is presented on potential CMOS circuit implementation of the proposed AESA for a linear array of eight antennas and maximum operational frequency of 1 GHz.
Keywords :
IIR filters; all-pass filters; array signal processing; direction-of-arrival estimation; interference suppression; linear antenna arrays; radio receivers; signal flow graphs; time-domain analysis; AESA receiver; CMOS circuit; DOA; SIR; active electronically scanned array; all pass filter-based 2D IIR beam filter; beamforming method; continuous time domain signal flow graph; direction of arrival; frequency 1 GHz; infinite impulse response; interference rejection; linear antenna array; nonuniform aperture weight; side lobe performance; signal processing model; signal-to-interference ratio; Array signal processing; Arrays; Broadband antennas; IIR filters; Interference; Radio frequency; Transfer functions; All-pass filter; antenna arrays; beamforming;
fLanguage :
English
Journal_Title :
Circuits and Systems I: Regular Papers, IEEE Transactions on
Publisher :
ieee
ISSN :
1549-8328
Type :
jour
DOI :
10.1109/TCSI.2014.2309833
Filename :
6779687
Link To Document :
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