The Design Of Dual-band Microstrip Antenna And LNA For WLAN Application

With the rapid development of wireless communication technology,there is an ever-increasing application scope of WLAN.With all kinds of WLAN standards upcoming,it's necessary to develop different antennas for WLAN application.In this paper,we focus on designing antennas used for WLAN IEEE802.11g standard, proposing a new Dual-band Microstrip Antenna.Analyze the structure of antenna, optimize the antenna with simulation software HFSS,the result indicates:The resonant frequency of this antenna are:2.45GHz and 5.25GHz,relative bandwidth are 3.3%and 13.1%,Satisfying with the protocol IEEE802.11g of WLAN.Low Noise Amplifier(LNA) is an important component of the RF receiver front-end circuit.Generally,for all types of radio-frequency or IF radio receiver,it is used as first-stage amplifier.It requests noise figure(NF) as small as possible,at the same time the gain as great as possible.This article describes how to design a linear small-signal low-noise amplifier by ADS of the entire process,including the selection of Dielectric substrate,stability analysis,bias circuit design,input and output matching circuit design,optimization of the overall circuit,components and microstrip line's replacement,the printed circuit patterns and so on.Ultimately,Aavgo Technologi es ATF-34143 chip is used to design a LNA,which noise figure less than 0.7dB,gain higher than 12dB,Gain flatness less than or equal to 1dB,input and output return los ses more than 10dB,the work voltage is 5V,Input and output impedance of 50Ω,the amplifier completely covers 2.4GHz-2.48GHz band,Fully meet the expectations of the design goals.