Design Of Massive MIMO Patch Antenna Arrays And Wideband Printed Antennas

As the new generation wireless mobile communication network, the fifth generation mobile communication systems have received widespread attention for their advantages of higher data rates, larger network capacity and millisecond level end-to-end latency. Massive MIMO antenna arrays have enormous advantages in spectrum efficiency, energy efficiency and reliability and have been one of the key technologies for 5G. At the same time, a wideband antenna design is necessary considering the downward compatibility of the new generation mobile communication systems. In consideration of the practical requirements of commercial mobile communication systems, this thesis mainly concerned with the Massive MIMO patch antenna arrays and the novel design of wideband dual-polarized and circularly polarized antennas. The author's major works and contributions are as follows:1. A single polarized antenna element fed by coupled slots is designed. Based on the analysis of different coupled slots' influence on antenna's electrical performance, a single polarized antenna element fed by “H” shaped coupled slot is designed by regulating the patch's size and slot's size, solving the mismatch problem resulting from the offset of coupled slots and feed line.2. A 8×8 MIMO patch antenna arrays are designed. The patch fed by coupled slots is chosen as the array element, which realizes ±45° dual-linear polarization by exciting two orthogonal “H” shaped coupling aperture slots etched on the upper ground plane. The deterioration of S21 resulted from patch's 45 ° rotation is improved by reducing the patch size and the introduction of a new manipulated variable. Test results show that the antenna arrays meet the design requirements. Compared with traditional crossed dipole, the proposed antenna arrays have advantages such as low profile, compact structure and easy integration with RF front-end, which can meet the demand of the antenna arrays for 5G mobile communication systems.3. A wideband antenna element fed by coupled slots is designed by multi-patch resonance method. Firstly a wideband single polarized antenna element is designed with stacked patches to enhance the bandwidth. By adjust the patches' size and the distance between the patch and the ground, a dual-polarized antenna element is designed with stacked patches covering 3.2GHz-4.2GHz with |S11|<-10 d B and |S21|<-34 dB.4. A wideband circularly polarized printed antenna is designed. The circularly polarized printed antenna is fed by coplanar waveguide(CPW). Two stubs are embedded in the CPW feed line to excite circular polarized. Test results show that the proposed broadband circularly polarized antenna maintains impedance bandwidth of 57% and axial ratio bandwidth of 50%.