Research On Multi-layered Wideband Antennas And Arrays

Compared with the single-layered antenna,the multi-layered antenna merits better performance and multi-function without increasing the transverse dimension.The increasing of the vertical dimension is more acceptable than that of the transverse dimension,especially in the application using the rising multi-layer technology,such as multi-layer silicon-based technology and low temperature co-fired ceramic?LTCC?technology.Besides,in high frequency band,such as millimeter-wave band,the increasing of the vertical dimension do not deteriorate the miniaturization and integration.On the other hand,because of the advantages of high transmission rate,penetrability,flexibility,location ability and so on,wide band becomes another important technology.Recently,wide band technology has become a hot research topic.Researches on the analysis of the multi-layered wideband antenna and array have been done in this dissertation.Based on LTCC and the combination of the substrate and metal shell technologies,the multi-layered antenna and array are achieved by using four technologies:1.Based on LTCC,the bandwidth of the proposed dipole antenna is widened greatly by introducing a resonant loop.The dipole antenna is not fed by wideband balun and its size is not increased.Then,the dipole antenna is implemented to form a 2?2array.The array is fed by T-shaped microstrip network with equal amplitude and phase.In the end,the dipole antenna and array prototypes are built and measured.The measured results show that the dipole antenna has a-10-dB-S₁₁ bandwidth of 25.4%covering the frequency range of 31.2 to 40 GHz and a maximum gain of 4.4 dBi at 32GHz.The dipole array has a-10-dB-S₁₁ bandwidth of 28.6%covering the frequency range of 30 to 40 GHz and a maximum gain of 10.37 dBi at 31 GHz.2.Based on LTCC,the bandwidth of the proposed dipole antenna is widened greatly by introducing a resonant slot on the upper ground of the feeding substrate integrated waveguide?SIW?.Because of the feeding SIW,the dipole antenna also has the merit of low loss.Then,the dipole antenna is implemented to form a 2?2 array.The array is fed by T-shaped microstrip network with equal amplitude and phase.In the end,the dipole array prototype is built and measured.The measured results show that the dipole antenna has a-10-dB-S₁₁ bandwidth of 19.5%covering the frequency range of 32.9 to 40 GHz and a maximum gain of 11.5 dBi at 32.5 GHz.3.Based on LTCC,the circularly polarized?CP?antenna and array with both wide impedance matching and axial ratio?AR?bandwidths are achieved by using the sequentially-rotated technology.The antenna has two patches with diagonal perturbations fed by L-shaped probe.The patch is printed on a thick substrate and fed by an L-shaped probe,so the impedance matching bandwidth is wide.Besides,a sequentially-rotated array is built in the antenna,so the AR bandwidth is also wide.The array is fed by T-shaped stripline network with equal amplitude and phase.Then,the patch antenna is also implemented to form a 2?2 array.In the end,the array prototype is built and measured.The measured results show that the patch antenna has a-10-dB-S₁₁ bandwidth of 29.6%covering the frequency range of 29.7 to 40 GHz,a3-dB-AR bandwidth of 26%covering the frequency range of 29 to 39 GHz and a maximum gain of 9.3 dBi at 31 GHz.4.Based on the combination of the substrate and metal shell technology,a wideband SIW-fed conical-horn-loaded CP SIW wide slot antenna with both wide impedance matching and AR bandwidths is proposed.This antenna can solve the problem of the narrow bandwidth and low gain of the traditional SIW CP antenna.The antenna has three parts:a short-ended SIW,a center-symmetric wide slot,an L-shaped probe.The L-shaped probe is connected to the center of the SIW and extends to the center-symmetric wide slot.In the end,the antenna prototype is built and measured.The measured results show that the antenna has a-10-dB-S₁₁ bandwidth of28%covering the frequency range of 30 to 40 GHz,a 3-dB-AR bandwidth of 22.2%covering the frequency range of 32 to 40 GHz and a maximum gain of 15.6 dBi at 36GHz.