Design And Implementation Of A WLAN Band Bidirectional Amplifier

With the rapid development of communication industry and the maturity of communication infrastructure construction,wireless communication is rapidly integrated into people's daily life with its incomparable advantages.With the increase of the number of users and the diversification of communication services,wireless local area network has become an extension of wired network because of its strong mobility and easy expansion.As a typical representative of WLAN technology,WIFI limits the network coverage of related products because its communication protocol standard stipulates that the transmitting power of WIFI products is not more than 100mW.Based on expanding the coverage of this kind of products,a bidirectional amplifier for WLAN band is developed in this paper.The main contents of this paper are as follows:(1)Linear regulated power supply chip is used to build power supply circuit,and parallel coupled line directional coupler,detection circuit,voltage following and voltage comparison circuit are used to build voltage switching control circuit.(2)The RF switching circuit,step-by-step adjustable attenuation circuit,power amplifier circuit and low noise amplifier circuit are constructed by choosing chips respectively,and the corresponding plate making,welding,debugging and single board function testing are carried out.(3)The power supply and voltage control circuit,as well as radio frequency related electronic circuits are logically spliced and integrated,and the final version of the bidirectional amplifier is designed,processed and tested.In this paper,ADS2015 is used to complete the simulation of parallel coupled line directional coupler.Altium Designer software is used to build each sub-circuit,and finally complete the design of bidirectional amplifier.The test results show that the output power of the bi-directional amplifier branch reaches 25dBm,the gain is 23dB,the return loss is more than 12dB,and the gain of the low noise amplifier branch is 19dB,the noise figure is 3.8dB,and the return loss is more than lOdB.