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On the Design of Circular Fractal Antenna with U-Shape Slot in CPW-Feed
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作者 Raj Kumar 《Wireless Engineering and Technology》 2010年第2期81-87,共7页
A new ultawideband circular fractal antenna with notched-band characteristics is presented. A notched-band characteristic is achieved by employing a U-shape slot in 50 Ω feed lines. The ultra-wideband impedance match... A new ultawideband circular fractal antenna with notched-band characteristics is presented. A notched-band characteristic is achieved by employing a U-shape slot in 50 Ω feed lines. The ultra-wideband impedance matching and compact size have been obtained by using CPW-feed technique and the fractal concept. The measured result of proposed fractal antenna exhibits the ultra wideband characteristics from 3.0 to 18.0 GHz at VSWR 2:1 except notched-band frequency. The proposed antenna has been analyzed theoretically and experimentally with respect to design parameters. The measured radiation pattern of fractal antenna is nearly omnidirectional in azimuth plane throughout the operating frequency. This antenna is useful for UBW communication system. 展开更多
关键词 MONOPOLE ANTENNA Wideband ANTENNA Resonant Frequency FRACTAL Antennas multib ANTENNA
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1994年以来出口退税率的过度调整及其原因 被引量:11
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作者 韩媛媛 高德步 《涉外税务》 CSSCI 北大核心 2010年第4期8-12,共5页
考察中国出口退税率变化的基本情况,可以发现1994年以来出口退税率调整存在过度倾向。从表面来看,调节出口规模、减轻中央财政压力和支持产业结构调整等多重政策目标是出口退税率过频过大调整的原因,但是问题的根源还主要在于出口贸易... 考察中国出口退税率变化的基本情况,可以发现1994年以来出口退税率调整存在过度倾向。从表面来看,调节出口规模、减轻中央财政压力和支持产业结构调整等多重政策目标是出口退税率过频过大调整的原因,但是问题的根源还主要在于出口贸易调控工具的有限性、出口退税负担机制改革的不彻底以及产业结构调整政策体系的不健全。 展开更多
关键词 出口退税率 过度调整 多重目标
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