Dielectric Resonator Antennas And Dual-band Dual-polarized Microstrip Arry Antennas

With the spectrum resources being developed and applied, the techniques of wideband, miniaturization and dual-polarization are increasingly important in the wireless communication system in the future, especially for national economy and military applications, such as the satellite communications, electronic warfare systems, etc. Thus this dissertation proposes the novel designs of wideband and dual-polarization dielectric resonator antenna with high isolation and a wideband circularly polarized rod antenna, finally, a new type of dual-polarization and dual-frequency multilayer-stacked microstrip array antenna is introduced with experimental verification. Three main subjects are included:Firstly,A new design of dual-polarized dielectric resonator antenna with high isolation over a wide bandwidth is introduced, which isfed by utilizing the bowtie-shaped slot coupling. Four identical bowtie slotsare arranged symmetrically in an unconnectedcross configuration in the center. The isolation between two orthogonalpolarizations of the proposed antennais greatly improved over theconventional cross slot.The proposed antenna prototype has been fabricated and measured. Both simulated andmeasuredresults show that the proposed antenna has a port isolation of about40 dB over the impendence bandwidth(|S11|≤10d B)of 28-30%.Moreover, stableradiation patterns anda peak gain of 5.0–6.4dBi areachieved within the operating band. Its good polarizationpurity and broadside radiation patterns are confirmed also.Secondly,The design of a low-sidelobe circularly-polarized rectangular dielectric resonator antenna array is presented. In addition, a novel, simple and generic transmission line circuit model is developed. The proposed antenna prototype has been simulated. The results verify that it exhibits advanced characteristics with an impedance bandwidth(VSWR ≤ 2) of 6.03%, an axial ratio bandwidth(AR ≤ 3 dB) of 6.91%. Its simulated maximum gain is 11.7dB with a gain variation of 2.2dB over the bandwidth.Thirdly,A new type of dual-polarization and dual-frequency multilayer-stacked microstrip array antenna is introduced. The feeding mechanism of the element is the aperture coupling for one polarization and the direct feeding for the orthogonal polarization. The microstrip element exhibits a wideband of operation. A slot etched on driven patch is used to improve isolation performance of the proposed antenna element, and the better impedance characteristic is obtained as well. Measured results agree well with the simulation, exhibiting a |S11|≤10dB bandwidth of 16.6% in V-port and 14.28% in H-port. The measured isolation is better than 33.3dB. Good radiation patterns and low cross-polarization level are also confirme...