The Design And Simulation Of 5.2GHz Wireless Local Area Network Front-End Circuits

While computers and communications technology are exploding, Wireless Local Area Networks are prevailing increasingly in personal and commercial computer field. WLAN are evolving toward using higher frequencies, wider bandwidth and more functionality to satisfy growing demands of users worldwide. IEEE802.1 la is one of best wireless protocol standard. IEEE802.1 la standard works in the 5 GHz band and uses OFDM modulation, transport speed is 6~54Mbit/s.With increasing frequency and adding bandwidth, design of RF circuit is harder and harder. Tools of accessorial computer analysis and synthesis are underway, the results of these tools only can be references. So design of RF circuit is dependent to a great extend on test and experience of designer. The paper has discussed RF front-end design and simulation according to IEEE802.1 la standard of WLAN with ADS.In this paper the main work is done as following:First, the standard of WLAN is introduced, and the general design theories and methods are discussed. Then, we design and simulate separately link budget calculation of the transmit-receive RF system, getting circuit system in accordwith the standard. Last, we customize the specifications according to link budget calculation, and finish the design and simulation of subcircuits. The subcircuits consist of the low noise amplifier, RF filter, mixer, driver amplifier, image filter, power amplifier, transmit-receive switch and IF filter and so on. We design mainly amplifier, including modeling high frequency modulation designing DC bias analysing gain of amplifiers. Finally, We use the same broadband amplifier to finish IF amplifier in the 480MHz band and gain amplifier in the 5GHz band with different matching.