DocumentCode :
1516974
Title :
Optimum design of feed structures for high G/T passive and active antenna arrays
Author :
Demir, Simsek ; Toker, Canan
Author_Institution :
Dept. of Electr. & Electron. Eng., Middle East Tech. Univ., Ankara, Turkey
Volume :
47
Issue :
3
fYear :
1999
fDate :
3/1/1999 12:00:00 AM
Firstpage :
443
Lastpage :
452
Abstract :
In this work, noise analysis of parallel feed structures is presented. Signal and noise behavior of the feed structures are signified by the newly introduced concepts of “coherent” and “incoherent” impedance match of power-combining structures. It is also shown that a feed structure can be redesigned for low-noise operation without affecting the radiation characteristics. Optimum design of parallel feed structures for low-noise operation is explained. Also an optimum use of active elements in such structures is investigated to have a low overall noise temperature of the antenna array with minimum number of active elements. In the analysis, a new method is introduced where a “noise-equivalent line length” (NELL) is defined. This definition, which unifies the contribution of noise from different array elements, is used in the design of a parallel feed structure and as an active circuit replacement criteria in passive arrays
Keywords :
active antenna arrays; antenna feeds; antenna radiation patterns; impedance matching; microstrip antenna arrays; noise; optimisation; transmission line theory; active elements; coherent impedance match; high G/T active antenna arrays; high G/T passive antenna arrays; incoherent impedance match; low-noise operation; noise analysis; noise behavior; noise-equivalent line length; optimum design; parallel feed structures; patch antenna array; radiation characteristics; signal behavior; Active noise reduction; Antenna arrays; Antenna feeds; Antenna measurements; Circuit noise; Costs; Impedance matching; Noise measurement; Receiving antennas; Signal to noise ratio;
fLanguage :
English
Journal_Title :
Antennas and Propagation, IEEE Transactions on
Publisher :
ieee
ISSN :
0018-926X
Type :
jour
DOI :
10.1109/8.768778
Filename :
768778
Link To Document :
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