The Design Of Planar Waveguide Cts Antenna

The Continuous Transverse Stub (CTS) antenna is implemented with an array of continuous transverse radiating stubs extending from the upper conductive plate of an open parallel-plate transmission-line structure, and internally excited by a TEM mode linear source. It is an important topic of for high gain antennas due to its high feed efficiency and aperture efficiency. CTS array is also convenient for beam-controlling and dual-polarization application and has advantages of ease fabrication and low cost, which promise it broad application prospects. In this thesis, design on plane CTS arrays and low-loss TEM mode linear sources are investigated as follows.Firstly, the radiation mechanism of CTS element is analyzed. An element model with periodic boundary is established to conduct simulation research on the relationship between structure parameters and radiation performances of CTS element. For a prescribed stub length in SIW CTS array scheme, a technique of metallic diaphragm loading is proposed to achieve desired impedance matching and optimized radiation for CTS elements.Secondly, the design of planar CTS arrays is intensively discussed with planar wave excitation through planar waveguide. A CTS resonator array and a non-resonant array are discussed respectively, and the performances of them are compared. Then, a novel small CTS array with stepped optimized input impedances is further proposed to improve radiation efficiency with moderate bandwidth. An8-element CTS array and its line source are discussed in following chapters.Thirdly, SIW line sources are designed to provide planar wave excitation for CTS antenna array. A T-junction transition is introduced to transfer the TE10mode in waveguide to TEM mode in planar waveguide. For the radiation waveguide with metal wall boundary, terminal matching structure is designed to improve the planar wave distribution. Both corporate-feed and series-feed source have been designed.Based on the above research, an ensemble of8elements CTS array with SIW series feed is designed and optimized. Thickness of3.175mm Rogers5880substrate is used for the feed and radiation waveguide, and standard PCB processing technology are adopted. Finally, the CTS antenna array is fabricated and measured, and measured results show that an impedance bandwidth of12.27GHz-12.92GHz and relative bandwidth5.2%is obtained under the condition of S11<-10dB, and a gain of24.77dBi at12.5GHz, and a corresponding efficiency of34.6have been achieved. Good agreements between simulated and measured results are observed, which demonstrate the effectiveness and feasibility of our design method.