Planar compact low-coupling four-polarization MIMO antenna based on orthogonal mode

Abstract

The invention discloses a planar compact low-coupling four-polarization MIMO antenna based on an orthogonal mode, which comprises a first radiator and a second radiator based on the orthogonal mode, the first radiator adopts an annular structure, the second radiator adopts a microstrip patch structure, a radiation mode of an electric dipole (Ex) and a magnetic dipole (Hz) is obtained on the first radiator, and two orthogonal TM11 microstrip antenna modes (Hx, Hy) are obtained on the second radiator. According to the invention, the internal space of the first radiator is fully utilized, the second radiator is arranged in the first radiator, four polarization modes are obtained in a planar structure, and the antenna has the characteristics of compact structure, low coupling and the like; the TM11 mode working frequency of the second radiator is reduced through the fractal structure, and the second radiator and the first radiator work in the same frequency band. According to the invention, the vector characteristics of the electromagnetic field are effectively utilized, and the channel capacity greater than 3 * 3 and close to 4 * 4 independent identically distributed Rayleigh channels can be obtained in a multi-path rich propagation environment through a compact structure.

Description

technical field [0001] The invention relates to an antenna, in particular to a planar compact low-coupling four-polarization MIMO antenna based on an orthogonal mode, which can be used in the fields of wireless communication, large-scale MIMO antenna array and the like. Background technique [0002] With the vigorous development of wireless communication technology, spectrum resources are becoming increasingly tight, and it is an inevitable trend to develop and utilize existing frequency bands as much as possible and improve spectrum utilization. Multiple-Input Multiple-Output (MIMO for short) technology can establish multiple parallel spatial sub-channels by using multiple transmitting antennas and receiving antennas at the transmitting end and receiving end respectively, without increasing spectrum resources and antennas. In the case of lower transmit power, the system channel quality can be doubled. In recent years, with the development of large-scale and ultra-large-sca...

AI Technical Summary

Problems solved by technology

Because it is difficult to realize multi-polarized antennas with co-point orthogonality, low coupling and compact structure, most of the existing multi-polarized antennas adopt the design of dual-polarized and triple-polarized antennas, while for four-polarized and more Polarized antenna designs are relatively rare

[0004] The disadvantages of the prior art mainly include: (1) Compared with the loop antenna, the structure of the electric dipole is relatively simple, and it is easier to obtain a low-coupling multi-polarized antenna through different polarization directions, but it cannot be used in space. Magnetic field components are fully utilized

However, in a multi-polarized antenna composed of an electric dipole and a loop antenna, the coupling between the electric dipole and the loop antenna is difficult to remove, especially in the case of coplanarity, and it is usually necessary to add a decoupling network , EBG and other structures to improve port isolation, so the design of multi-polarized low-coupling electromagnetic dipole antennas composed of electric dipoles and loop antennas is more difficult

(2) In order to obtain the orthogonal electric field and magnetic field components, it is usually necessary to place the electric dipole antenna and the loop antenna unit orthogonally, and the three-dimensional structure formed by this will increase the difficulty of design and processing

The four-polarization MIMO antennas currently proposed are all three-dimensional structures, and the antenna structure and feed network are complex, which is not conducive to integration, and it is difficult to be applied in some specific usage scenarios.

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