The Design Of Low-noise Amplifier Based On The 802.11 Standard

The rapid development of wireless communication, electronic countermeasure and satellite communication system, and the continuous advancement of manufacturing process, makes the wireless communications products are designed using microwave integrated circuits in a large scale, this is conducive to product miniaturization, and is more convenient to carry. Due to the low noise amplifier is located in the forefront of receiver system, its performance indexes can cause great influence to the wireless access system.This thesis designed two kind of low-noise amplifier, the first working frequency is 2.4GHz, the second is 5GHz. The design index satisfy 802.11 b/ac protocol, it can bring noise reduction and gain increasing to some extent for the wireless communication receiving system under this band. The main works of this dissertation are:(1)Through the analysis of the development of wireless network 802.11 protocol, obtained design index that meets the requirements from the original 2.4 GHz 802.11 b to now 5GHz 802.11 ac.Studied the basic design theory of low noise amplifier, and improved the common basic circuit.(2)The design of the 2.4 GHz low noise amplifier adopted monopole amplifying circuit, joined negative feedback circuit in the source. Through the stability analysis, the design of the bias circuit and the input and output matching circuit, the low noise amplifier of gain >15db, noise coefficient < 0.5 was designed.(3)Through the analysis of the circuit which adopt two-stage Cascaded, designed 5 GHZ low noise amplifier. Bias circuit adopted double power supply access method, negative feedback was joined after a primary circuit. Meanwhile, the matching circuit that can increase the bandwidth was designed. Finally, the low noise amplifier of gain >25db, noise coefficient <1.2 was implemented.