Feed network for reducing mutual coupling between antenna array units

Abstract

The invention discloses a feed network for reducing mutual coupling between antenna array units. The feed network can be used in wireless communication and a radar system. The feed network cannot damage initial impedance matching of the antenna array units, and therefore, an impedance matching network is not needed to be designed additionally. Meanwhile, controllable indirect coupling introduced into the feed network can be used for offsetting the direct coupling of the antenna array units on a radiation caliber so as to effectively reduce mutual coupling between the units. The feed network has the advantages of being simple in structure and small in loss and does not influence the radiation performance of an antenna. Two specific implementation forms of the novel feed network are provided, and specific simulation and test results of the examples are given at last.

Description

technical field [0001] The invention belongs to the fields of wireless communication technology and radar technology, and in particular relates to a novel feeding network that can effectively reduce mutual coupling between antenna array units, and is suitable for microwave, millimeter wave and other communication systems. Background technique [0002] In array antennas and multiple-input multiple-output systems (MIMO), mutual coupling of energy between elements is an unavoidable phenomenon and often negatively affects system performance. For example, in phased array antennas, the existence of mutual coupling will make it difficult to achieve impedance matching of elements in a large scanning range. For MIMO systems, the mutual coupling between units will lead to the deterioration of the signal-to-noise ratio and the reduction of the channel capacity. Therefore, how to reduce the mutual coupling between antenna array elements has always been a hot and difficult issue in the ...

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Problems solved by technology

In 2005, M.M.Nikolic et al. proposed to use several rows of short-circuit columns connecting the ground and microstrip patches to suppress the coupling of space waves; but these short-circuit columns will cause certain energy loss and are not easy to process

In 2008, C.Volmer et al. used a mode decomposition network to make the array scattering matrix orthogonal. However, the bandwidth of this method is relatively narrow, and the Q value and efficiency of different modes obtained by decomposition are also very different; in addition, this method also It is also necessary to design an additional matching network

In 2014, L. Zhao proposed to use reactance-loaded dummy arrays to reduce the mutual coupling between the active units of the symmetrical array, but the design process of the dummy array is relatively complicated, and the existence of dummy elements will also affect the radiation of the active units. performance

The method proposed in this patent provides a new idea for reducing the mutual coupling between array units, but the scheme described in the patent is difficult to implement

First, because the coupling section of the coupler is directly connected to the receiving link of the adjacent antenna, this will lead to the deterioration of the impedance matching of the adjacent antenna, and in addition, part of the signal directly coupled from the adjacent antenna in space will be recoupled to the transmitting antenna through the coupling section The transmission link thus affects the radiation performance of the transmitting antenna; second, the implementation scheme proposed in this patent can only be applied to the case where one of the dual antenna units is used as the transmitting antenna and the adjacent antenna is used as the receiving antenna. However, in MIMO systems, In many applications such as phased array antennas, adjacent antenna elements need to be used as transmitting or receiving antennas at the same time, so its application is greatly limited; third, the active coupler proposed in this patent will not only encounter In addition to the same problems as the passive coupler above, it also increases the complexity of the design and the energy consumption of the antenna system

[0006] The above method for reducing mutual coupling between units is difficult to achieve simple structure, low loss and does not affect the radiation characteristics of the antenna itself

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