Research On Key Technologies Of The Ultra-wideband High Gain Tapered Slot Antenna And Its Array

Modern communication,radar,imaging,radio astronomy,high power systems,and other military and civilian areas require antennas with wider bandwidth and higher radiation performances.UWB high-gain directional antenna and its array have become one of the important topics in the field of antenna research at home and abroad.Conventional broadband directional antennas such as horn antenna and parabolic antenna can achieve high gain,but their weight,high cost and large volume make them difficult to be integrated with microwave circuits.Printed log periodic antenna and Yagi antenna can only realize high-gain in a limited frequency band.Tapered slot antenna(TSA)is a typical traveling wave antenna,which has the advantages of large bandwidth,moderate gain,low cost,and ease of integration.However,due to the restriction of the antenna electrical size,it is hard to achieve good impedance bandwidth and radiation performance simultaneously.Under this background,we mainly study the UWB high-gain TSA and its array with stable radiation performances,and conduct the corresponding experimental verification to prove the feasibility of the proposed design method in this paper.The research content and research results include the following five aspects:1)A high-performance UWB antipodal exponential TSA(AVA)is presented.Aiming at the problems of weak directivity,impedance mismatch at low frequencies,and beam split and tilt at high frequencies of the conventional AVA,an UWB AVA with compact structure and stable performances is designed.The gradient-tilted ripple edge was proposed to improve the low frequency performance of the antenna.By optimizing the size and angle of the tilted ripple,the low cutoff frequency was effectively reduced and the in-band mismatch was improved by reasonably distributing the gradient value.Asymmetric diamond-shaped parasitic patch was used to improve the performances at high frequencies.The coupling between the radiating arms was enhanced by extending the length of the parasitic patch in the tapered slot.By combining the two methods,the UWB AVA antenna achieves stable radiation over 2.88-43.5 GHz with endfire gain of 5.4-13.7 dBi and size of only 0.38 × 0.7.2)A near-field metamaterial lens loaded Vivaldi antenna is proposed.Aiming at counteracting the negative influence of phase errors at antenna aperture caused by the spherical wave radiation mode,a near-field metamaterial phase compensation lens(PCL)is presented.The theory of dielectric PCL is analyzed and theoretically deduced in detail,and the improvement of the PCL on Vivaldi antenna gain is verified.Then,the metamaterial units are utilized to build PCL.For the coplanar Vivaldi antenna operating over 3.5-16GHz,single-and multi-layer medium frequency and high frequency PCL are designed,respectively.Compared to the conventional metamaterial loading technique,the gain enhancement of this method is more obvious.3)The dielectric-and metamaterial-covered TS A antenna are proposed.Aiming at improving the radiation performances of the TSA without altering the antenna profile,the dielectric covered structure is presented.The change of transmission mode of dielectric covered structure was theoretically analyzed,and the influence of dielectric parameters on impedance bandwidth and gain of the antenna was studied.Two different dielectric covered structures have been designed,respectively.The design procedure is summarized.In addition,the effect of dielectric covered structure on the cross-polarization level,beam pointing and gain of the UWB ATSA was also investigated.Finally,a thin metamaterial slab is used to construct the proposed structure for reducing the weight and cost of the UWB ATSA antenna.4)The mm-Wave substrate integrated waveguide(SIW)TSA antenna array is investigated.The reason for the gain singularity of the ATSA array is analyzed theoretically.A method to eliminate the gain singularity is proposed by adding the metallization vias to realize electrical connection after overlaping the radiating arms of adjacent antenna elements.Then,the dielectric covered structure is combined to enhance the array gain.The bending SIW structure is adopted to broaden the impedance bandwidth of the 1-to-8 power divided feeding the ATSA array.At last,a UWB high-gain SIW ATSA antenna array is realized in the mm-Wave band.5)A high gain X-band Vivaldi array antenna is presented.The difference of the radiation performances between the edge element and the elements at other positions of the Vivaldi antenna array in a weakly coupled environment is studied in detail.And then the influence of the edge cells on the performance of the array is investigated.The idea of modifying the edge element to compensate for the performance degradation of the array introduced by the position difference is proposed.The array gain is improved by using the edge ripple.Finally,an X-band high gain Vivaldi antenna array is designed.