Verification Of The Key Technology Of 4 Channel Radio-frequency Circuit Of IEEE802.11 Ac

With the popularization of smart devices and the rapid development of wireless networks,users need more convenient ways to transmit large amounts of information.IEEE 802.11 ac,as the recently proposed WLAN standard,has great advantages in terms of high transmission rate and high throughput.According to the specific requirements of 802.11 ac standard,this paper studies and validates the key technologies of RF circuits in the frequency range of 5170MHz~5835MHz,and provides the necessary hardware platform for the research of 802.11 ac standard technology.The main work of this paper is as follows:Firstly,this paper briefly introduced the development history of IEEE802.11 standards and the characteristics of different versions,analyzed the structure of common transceivers,the applicable occasions of different structure transceivers,as well as their respective advantages and disadvantages.Secondly,according to the requirements of 802.11 ac standard for key radio frequency technical indicators,the key technical indicators such as radio frequency front-end working method,vector error magnitude,and adjacent channel power ratio are determined.And based on the application scenarios and key technical indicators,the superheterodyne structure is chosen as the RF front-end transceiver structure of this paper.Thirdly,the main technical indexes of RF transceivers,local oscillators and calibration channels are analyzed,and the specific requirements for the power range,in-band fluctuations,leakage of local oscillators and other indicators of the transceiver channels are determined,and the structural design of each channel of the RF front-end is completed.Through the spurious budget when the intermediate frequency is selected,the intermediate frequency of the transceiver channel is determined.According to the requirements of the indicator,the appropriate device is selected,the budget of key parameters such as gain,noise figure,input and output power,and linearity of the channel is estimated,and the key components in the link are analyzed,and performance simulation and optimization are performed on devices that do not meet the performance requirements.Finally,a test platform is set up to test the key parameters of sending and receiving RF front-end circuits with four channels reception front-ends,as well as debugging and analyzing the indicators that do not meet the design requirements.According to the problems that arose in the actual process,further research directions are proposed.On the bases of the work above,this paper designs and implements a four channels RF front-end circuit based on the IEEE802.11 ac standard.This circuit could achieve 4 channels transmit and 4 channels receive,support the bandwidth of 20 MHz,40MHz,80 MHz,160MHz and 80MHz+80MHz.It also meets the actual application requirements of high-speed and multi-channel,which has certain reference significance for the verification of the key technology in 802.11 ac standard.