Ultrabroadband 4 × 4 Butler matrix with the use of multisection coupled-line directional couplers and phase shifters
2006 ◽
Vol 54
(11)
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pp. 3986-3994
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2006 ◽
Vol 54
(9)
◽
pp. 3501-3507
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2011 ◽
Vol 59
(10)
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pp. 2441-2446
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1963 ◽
Vol 110
(5)
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pp. 869
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