Research And Design Of LNA For CMMB Application

With the promulgation of CMMB (China's Mobile Multimedia Broadcasting), as the de facto standard of mobile TV in China promoted by SARFT, the emerging market of mobile TV in China is undoubtedly booming prosperously during the past 2 years. CMMB systems have been implemented as information platform for city railway transmission system, and accordingly, the CMMB application is gradually integrated with various kinds of mobile appliances, i.e. mobile phones and notebooks. Providing a high performance but low cost solution of RF-frontends arouses the interest of researchers and equipment providers.In this dissertation, he author will mainly discuss a wideband varia-ble-gain LNA designed for CMMB application under the restriction of low power consumption and low cost.The topics of this dissertation mainly comprise: introducing the fun-damental concept of LNA, including impedance matching, noise, linearity and etc; providing introduction to CMMB system and application; de-scribing the design method of wideband LNA, including the analysis of specification and circuit; and exploring the possibility of achieving better performance and improvement.The simulation results indicate that the proposed LNA provide gain modes ranging from 18dB to -3dB with a 6dB step. The LNA exhibits an IIP3 of 5dBm and an NF of less than 2.8dB at high gain mode, with a power consumption of less than 12mW from 1.8V voltage supply.