Design Of Ku-band Broadband High-Gain Substrate Integrated Cavity Circular Polarization Array Antenna

Compared with linearly polarized antennas,circularly polarized antennas have been widely used in remote control,telemetry,radar,and satellite communications due to their own characteristics,especially in Ku-band satellite communications.With the rapid development of modern communication technology,higher requirements have been placed on the performance indicators such as the bandwidth and gain of circularly polarized antennas.Substrate Integrated Cavity(SIC)antennas have a small size,high gain,and can be effectively suppressed Surface waves and other advantages have become one of the research hotspots in the field of antenna design.Based on the SIC structure,carrying out Ku-band broadband,highgain circularly polarized antenna design research has clear application value and practical significance.The main work of this article is as follows:1.Two Ku-band broadband,high-gain SIC circularly polarized element antennas operating in higher-order modes are proposed.First,by analyzing the field distribution on the aperture surface of the cavity antenna of different sizes,it is proposed to increase the aperture surface of the cavity and introduce two semi-circular parasitic patches placed obliquely at a45° angle to achieve z-directional circular polarization radiation of the antenna aperture.Then,the effects of some main parameters of the unit antenna are studied by simulation,the radiation mechanism of the antenna is analyzed,and a broadband high-gain circularly polarized unit antenna is obtained through simulation optimization.On this basis,a patch-stacked circularly polarized element antenna is proposed to achieve an improvement in operating bandwidth and gain.2.Based on the proposed SIC circularly polarized element antenna,three types of 2×2element circularly polarized array antennas were designed.First,a 2×2 element SIC circularly polarized array antenna with equal-radial in-phase feeding is proposed.Then the problem of poor axial ratio of the array antenna is analyzed,and using the principle of sequential rotation feeding,a double-layer substrate integrated waveguide power division feeding network is designed.The SIC circularly polarized array antenna composed of sequentially rotating feed realizes the expansion of bandwidth.Finally,in order to obtain a higher gain,an array antenna was designed using the patch stacked circular polarized element antenna proposed in this paper and a single-layer SIW equal amplitude in-phase feed network,the array antenna can better meet the needs of Ku-band satellite communication applications.