| At present, communications require more and more multimedia, diversification, high-bandwidth. Wired network has been perfect, and many places have achieved Wi-Fi coverage. But in many cases, for specific applications, quickly establishing a dedicated wireless access system is needed, the system can provide high-bandwidth access to facilitate the realization of mobile or nomadic communications in the range of tens of kilometers. According to the situation the system can choose their own network, or connect to other private or public network via a node of the network. Because of the low RF output power of the board itself, in order to achieve a more far-distance transmission, this thesis developed a bidirectional high power amplifier applied in the 750 MHz ~ 790 MHz following the IEEE802.11 b / g / n protocol. By increasing the output power of the device this amplifier achieved long-range, high-bandwidth transmission. This amplifier consists of a detector, power amplifiers, RF switches and other components. The maximum output RF power 40 d Bm, P1 d B of about 53 d Bm, low noise partial use MAAL-010705 to design, the smallest gain 18 d B, noise figure of only 0.5d B; amplifier chip using NXP's 200 W high-power IC design, to ensure that EVM value to meet the requirements when the output power is 40 d Bm.The major task of this dissertation is to design a power amplifier module and a low noise amplifier for a RF communication system which work in the frequency from 750 MHz ~ 790 MHz.work if 3 aspects is chiefly carried out as follows:1. Analysis of the special nature of the modulation scheme used in the system of linear power amplifier requirements.2. The use of simulation software to determine the optimal load impedance, designed the indicators power, linearity, gain, etc. to meet the design requirements of the power amplifier.3. The use of simulation software analysis and optimization problems encountered in the design of low-noise amplifier, shorten the time to debug the circuit. |
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