Research And Design Of Miniaturized Antenna Based On Composite Right/left-handed Transmission Lines

With the continuous upgrading of communication system,the performance requirements of the system are gradually improving,and the space left for RF devices in the system is becoming smaller and smaller,so the miniaturization of RF devices is particularly important.Composite right/left-handed(CRLH)transmission line can not only combine left-hand and right-hand transmission lines at the same time,but also the negative and zero order modes besides the positive mode.Whether in the negative and zero order resonant modes,the resonant frequency is not limited by the physical size of the device.CRLH transmission line can be used in antenna,which is of great significance to the miniaturization of the antenna.Therefore,based on the CRLH transmission line theory,this thesis analyzes and designs the antenna to realize miniaturization.The main contents of this thesis are as follows.Firstly,based on the non-resonant composite right/left-handed transmission line,the loaded lumped elements are used to realize the miniaturization of the antenna.A T-type CRLH transmission line with 5.0 GHz zero order resonant frequency is designed by using folded line structure and asymmetric coplanar waveguide feed.Then a?-type CRLH transmission line with zero order resonant frequency of 2.3 GHz is designed by using double helix,interdigital and metal via.The CRLH transmission line designed above is applied to the antenna,and the PIN diode loaded with lumped element is used to realize the frequency conversion by using the different working states of the diode.Both antennas can realize the characteristics of adjustable frequency.The size of T-type and?-type non-resonant CRLH transmission line antenna is 0.116?₀×0.203?₀×0.015?₀ and0.127?₀×0.117?₀×0.012?₀,respectively.Then,based on the resonant composite right/left-handed transmission line,the antenna is miniaturized by meandering slot.Based on the theoretical research of substrate integrated waveguide(SIW)resonator,the split ring resonator(SRR)and the complementary split ring resonator(CSRR)are introduced to realize the CRLH transmission line characteristics.By using the meander slotting technology and adding a CSRR structure,the frequency can be reduced without changing the size.Then,four element SRR and four element CSRR are loaded into the triangle SIW cavity.Because of the shape of the triangle,the triangle SIW resonator is more compact than the rectangular SIW resonator with the same mode.The rectangular SIW resonator and the triangular SIW resonator not only realize the miniaturization of the antenna,but also have high gain.The size of the rectangular SIW resonator antenna and the triangular SIW resonator antenna is 0.587?₀×0.719?₀×0.012?₀ and 0.414?₀×0.558?₀×0.010?₀,respectively.Two kinds of CRLH transmission line antennas are fabricated and tested.The test results are basically consistent with the simulation results.Compared with the related literature,the antennas designed in this thesis have excellent performance and miniaturization in size,which have a certain practical application value in the field of communication.