Design Of Polarized Duplex Antenna For WLAN Frequency Band

Co-time co-frequency full duplex(CCFD)communication has the advantages of saving the spectrum resources and improving the band utilization,so it has attracted people’s attention in recent years.In the CCFD system,the polarized duplex antenna is a key device.Therefore,it is of theoretical and practical significance to study the high performance polarized duplex antenna with high isolation and wideband characteristics.The polarized duplex antenna requires that the antenna has a dual polarization characteristic.At present,there are many ways to realize the dual polarized antenna.Among them,the microstrip patch antenna has the advantages of simple structure,small volume,light weight,conformable to the carrier,easy integration with microwave active devices and circuits,and using the same patch can receive and send two non-interference electromagnetic waves with the orthogonal polarization.Therefore,this paper uses the microstrip patch antenna structure to design polarization duplex antenna used in the WLAN system.In this paper,a high-resolution dual-polarized microstrip patch antenna operating in the 2.4GHz WLAN band is designed.The antenna is a stacked microstrip patch structure,and two adjacent resonant frequencies are introduced through two layers of radiation patch,Thereby widening the frequency band of the antenna.The feed mode is mixed feed,the horizontally polarized port is the microstrip line feed,the vertical polarization port is the gap coupling feed,and the coupling gap adopts the H-type gap with high coupling efficiency.As the microstrip antenna uses a hybrid feed mode,two microstrip feeders are placed on both sides of the slotted ground plate,shielding the interference between each other and improve the isolation between the ports.On the basis of this,the antenna is used as the unit antenna,and the 2×2 antenna array is formed by using the misalignment feed.The isolation between the ports is optimized,and the cross polarization level in the main lobe is effectively suppressed.In this paper,three equally divided Wilkinson power splitter is used to design a four-division divider by cascade and introduce a 180° phase shifter to achieve the purpose of inverting feed.Then,this paper also designed a broadband dual-polarized antenna work in the 5.2GHz and 5.8GHz WLAN band.The antenna uses a square ring gap structure,the overall shape of the stepped rectangle.The adjacent arms of the girth are fed through the microstrip line to produce two mutually orthogonal electromagnetic fields,while the introduction of the other arms causes the antenna structure to be symmetrical and reduces cross-polarization.By optimizing the groove arm and the size of feeding line,the required impedance matching and isolation are achieved.In this paper,the design of dual-polarized antenna and array is designed by the combination of theoretical design and electromagnetic simulation software,and the antenna is processed and tested according to the design result.The test results show that the design of the dual polarized antenna and antenna array basically meet the design requirements.