DocumentCode :
3272706
Title :
Hybrid mitigation of distortion in digital arrays
Author :
Rabideau, Daniel J.
Author_Institution :
Lincoln Lab., MIT, Lincoln, NE, USA
fYear :
2005
fDate :
9-12 May 2005
Firstpage :
236
Lastpage :
241
Abstract :
Radars and other RF systems are often used to detect weak signals in the presence of strong interference. Consequently, these systems must be designed to accommodate both (1) high SNR levels, and (2) high instantaneous dynamic range (IDR) levels. Recently, digital beam forming (DBF) techniques have been proposed as a means of improving both SNR and IDR. In a DBF system, high SNR levels can be produced by coherently combining many lower IDR transmit/receive (T/R) channels. However, this does not necessarily result in an equally improved IDR because distortion, which is introduced by the RF electronics within each T/R channel, could also be coherently integrated by the beamformer. The resulting integrated distortion could exceed the noise level at the beamformer´s output, thereby limiting IDR improvement. This paper describes an approach to increasing the IDR levels achieved by digital arrays. The approach combines traditional DBF techniques with new IDR enhancement measures. Dynamic range enhancement is achieved through the use of two complementary processes: (1) decorrelation of spurs, phase noise, and various intermodulation products, (2) linearization of selected intermodulation products. This approach provides an efficient means for reducing the broad range of distortion products that typically limit IDR.
Keywords :
array signal processing; decorrelation; intermodulation distortion; phase noise; radar signal processing; SNR; digital arrays; digital beam forming; distortion hybrid mitigation; dynamic range enhancement; instantaneous dynamic range; integrated distortion; intermodulation products; phase noise; spurs decorrelation; transmit-receive channels; Decorrelation; Distortion measurement; Dynamic range; Noise level; Phase noise; RF signals; Radar detection; Radio frequency; Radiofrequency interference; Signal detection;
fLanguage :
English
Publisher :
ieee
Conference_Titel :
Radar Conference, 2005 IEEE International
Print_ISBN :
0-7803-8881-X
Type :
conf
DOI :
10.1109/RADAR.2005.1435826
Filename :
1435826
Link To Document :
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