小型化宽带背腔缝隙天线.doc

Journal of Shanghai University(English EdiSon)，2007，11(6)：576-579 Digital Object Identifier(DOI)：10 1007／s 11741· 007-0610-2 Compact wideband cavity-backed slot antenna LIANG Xian-ling(粱仙灵)，ZHONG Shun shi(钟顺时) School of Communication and Information Engineering，Shanghai University，Shanghai 200072，P R China Abstract A wideband cavity-baRked slot antenna operated in the nltrarhigh frequency(UHF)band is introduced．The antenna has a compact structure and low profile with tile size ratio of tile ground plane to the slot only 1．6：1 The measured impedance bandwidth of VSWR≤ 3 achieves 85 3％．covering a frequency range from 390 MHz to 970 MHz The measured gain is about 5 5～7．5 dB． Keywords slot antenna，wideband，compact，ultrahigh frequency(UHF)． 1 Introduction The microstrip-fed slot antennas have found appli- cations in radar and communication systems due to various features such as wide impedaLIce bmldwidth． 10w profile．1ight weight．and easy integration with ae- tive devices or monolithic microwave integrated circuits fMMICs)．Therefore a large number of experimental and theoretical studies on the slot antennas have been carried out with different slot shapes and fed by dff- ferent microstrip line configurationst㈨J However few of them have been used in VHF／UHF band because of their large ground planes Since the antenna size of- ten imposes a significant limitation on the overall size of a wireless device especi“ly for the VHF／UHF band antelma miniaturization is highly desirable．In 12．a triple-offsets-fed by ring gr01『md slot antenna backed a plane high gain proposed with bandwidth and a a is The and and width radius of slot 26 the is mm length of the ground Diane respec- are 120 mill and 110 mm tively．with ground plane a size ratio of the to the slot being printed by 19．5：1．In 41．a wide-slot antenna fed a nficrostrip line with rotated achieves maximum a slot a impedance bandwidth the dimen- of 49％，where slot sion 24．7 nlID．x24，7 while is mm its ground plane is of 70 with m