The Research And Design Of A Wideband Vivaldi Antenna With Low RCS And Low Cross Polarization

With the development of Internet of things and wireless communication technology,more and more wireless terminals have challenged the speed of wireless test.As an important mean of the wireless test,the chamber test is widely used in various test scenarios,and the multi-probe chamber is the main method for fast test.In multi-probe chamber,the probe antenna is the main factor restricting the test precision.Aside from some common performances,the probe antenna in multi-probe chamber has high requirements for the antenna size,bandwidth,cross polarization and reflection performance compared to ordinary antenna.In order to obtain an antenna suitable for multi-probe darkroom,the primary works have been done in following aspects.1.Introduce the circuit model and basic parameters of the antenna,focusing on the standing wave,gain and pattern.The influence of these antenna parameters on the chamber test and the main methods to change these parameters are studied.2.The polarization wave and three definitions of antenna cross-polarization are studied.For the low cross polarization,the cross polarization performance of different types of slot lines is analyzed,and the slot line structure with the optimal crosspolarization performance is obtained.3.The basic definition of radar cross section(RCS)and the radar transmission equation are introduced.The antenna mode RCS and structure mode RCS are studied with S-parameters scattering mode.The main influencing factors of the two are clarified,and the influence of object shape on the structure mode RCS is discussed.In addition,in order to prove that the RCS of the probe antenna does influence the measurement results of the antenna,this paper also proposes and verifies a method to evaluate the chamber performance by using the antenna RCS.4.This paper introduces the classification of Vivldi antennas,studies and designs the basic components of Vivaldi antenna,namely the feed structure,the slot line transition structure and the radiator.The influence of absorbing material on the antenna performance is studied and a new cavity structure which has a large electric size and can effectively improve the low-frequency matching performance of the antenna is proposed.Base on the above work,this paper designs and produces a 0.4–6GHz broadband absorber-integrated Vivaldi antenna.This antenna can cover the frequency bands of most communication protocols and has the characteristics of small size,excellent cross polarization and reflection performance.It is a good candidate for the probe antenna in multi-probe chamber.