Design Of Multi-mode Waveguide Slot Antennas And Investigation Of Decoupling Between Array Elements In The W-band

With the coming of the Internet of everything,the low frequency data communication will also become increasingly saturated,the spectrum resources within 30 GHZ basically has already been used up,people will start aiming higher frequency communication,and as the frequency increased,frequency resources we use are more abundant,and the frequency resource is richer,it can bring higher data transmission rate,in addition to this,high multiplexing technology in wireless communication transmitting system people use,such as multiple input multiple output(MIMO)technology,can also greatly increase the channel capacity.The waveguide structure has the advantages of low conductor loss,medium loss and no radiation loss.As a result,waveguide slot antenna array is often the first choice in MMW frequency band and high gain antenna.In this paper,We start from the actual practice of the waveguide slot antenna array project,the antenna in the W-band is selected as an example.By means of step by step,we start from the single-polarized dual-mode single-pulse antenna array to the final dual-polarized,four-mode eight-channel Waveguide slot antenna array,Also,a series of explorations on decoupling between waveguide slot array elements has been discussed at the end of the paper.The main contents are as follows:Firstly,On the basis of the introduction of the transmission theory of waveguide,the radiation theory of waveguide slot antenna array,the feed theory and the engineering design of waveguide slot antenna,A design method for non 2n × 2m elements array is proposed by using cross power distributor in feeding network,Taking 28×96 elements monopulse antenna array in the W band as an example,the design process of using single polarization and double mode waveguide slot antenna array is enumerated on the basis of satisfying the requirements of engineering processing.It has 4%Bandwidth when VSWR<1.6,the beam azimuth side lobe<-24 dB,beam pitch side lobe<-20dB,and the gain has reached 40.5 dBi.The fully parallel feed structure and planar magic T structure provide strong support for the subsequent design of dual-polarization MIMO antenna.Then,On the basis of the monopulse antenna array,Using cross-shaped radial gaps,multilayer feeding networks,and sum difference networks.this paper proposes a dual polarization,support of four modes of eight channels can be used in the non-far field communication of all parallel feed waveguide slot MIMO antenna array,the antenna array of all indicators meet the requirement of diffusion welding process design.In the-10 dB matching bandwidth,the aperture efficiency of the 16×16 element antenna array is higher than 70%,and the gain is higher than 31.4 dBi.And eight channels can transmit data at the same time.The normalized channel capacity of the transceiver antennas within 0.2 meters(62 times of wavelength)is higher than 7.4.Finally,a series of explorations are made on the decoupling of antenna elements,especially for the waveguide radiation gap element with a small array spacing(0.5 wavelength),a metal decoupling surface is proposed to be constructed above the array element,and the coupling wave is offset by controlling the reflection wave generated by the decoupling surface,so as to increase the isolation degree between the array elements.